{
 "paper": {
  "school": "Raffles Girls",
  "year": 2022,
  "level": "P4",
  "label": "Weighted Assessment 1",
  "source_prefix": "Raffles Girls 2022 P4 Weighted Assessment 1",
  "has_answer_key": true
 },
 "questions": [
  {
   "n": 1,
   "type_id": 1,
   "question": "John completed his homework at 18 25. He took 2 h 47 min to complete his work. What time did he start?",
   "answer0": "14 38",
   "answer1": "14 48",
   "answer2": "15 38",
   "answer3": "15 48",
   "correct_answer": 2,
   "skill_id": 135,
   "difficulty_id": 2,
   "explanation": "Work backwards from the finishing time. 18 25 minus 2 h gives 16 25. Then subtract 47 min: 16 25 - 47 min = 15 38. So John started at 15 38.",
   "hints": [
    "Subtract the duration from the finishing time.",
    "Take away the hours first (18 25 - 2 h = 16 25), then take away the minutes."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q1",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (3) = 15 38."
  },
  {
   "n": 2,
   "type_id": 1,
   "question": "A football match started at 15 15 and it ended at 16 40. How long was the football match?",
   "answer0": "1 h 25 min",
   "answer1": "1 h 30 min",
   "answer2": "3 h 25 min",
   "answer3": "3 h 40 min",
   "correct_answer": 0,
   "skill_id": 135,
   "difficulty_id": 1,
   "explanation": "Find the duration from 15 15 to 16 40. From 15 15 to 16 15 is 1 h, then 16 15 to 16 40 is 25 min. Total = 1 h 25 min.",
   "hints": [
    "Count the whole hours first, then the extra minutes.",
    "15 15 to 16 15 is 1 hour; 16 15 to 16 40 is 25 minutes."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q2",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (1) = 1 h 25 min."
  },
  {
   "n": 3,
   "type_id": 1,
   "question": "How many $$\\frac{1}{2}$$ turns will the minute hand of a clock turn between 9.25 a.m. to 10.55 a.m.?",
   "answer0": "5",
   "answer1": "6",
   "answer2": "3",
   "answer3": "4",
   "correct_answer": 2,
   "skill_id": 141,
   "difficulty_id": 3,
   "explanation": "The duration from 9.25 a.m. to 10.55 a.m. is 1 h 30 min = 90 min. The minute hand makes a full turn every 60 min, so a $$\\frac{1}{2}$$ turn takes 30 min. 90 min $$\\div$$ 30 min = 3 half-turns.",
   "hints": [
    "First find the total time: 9.25 a.m. to 10.55 a.m. is 1 h 30 min = 90 min.",
    "A half turn of the minute hand takes 30 min; divide 90 by 30."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q3",
   "image_needed": true,
   "image_options": false,
   "image_file": "q3.png",
   "image_page": 1,
   "image_bbox": [
    0.5,
    0.71,
    0.66,
    0.86
   ],
   "image_loc": "clock face to the right of the options, lower portion of page 1",
   "notes": "Key: option (3) = 3. Clock illustration is decorative; not required to solve."
  },
  {
   "n": 4,
   "type_id": 1,
   "question": "Edward washed 8 cars on Saturday. He took 20 minutes to wash each car. He started at 07 00. At what time will he finish if he did not take any breaks?",
   "answer0": "09 00",
   "answer1": "09 40",
   "answer2": "10 00",
   "answer3": "10 20",
   "correct_answer": 1,
   "skill_id": 135,
   "difficulty_id": 2,
   "explanation": "Total washing time = 8 $$\\times$$ 20 min = 160 min = 2 h 40 min. Add to the start time: 07 00 + 2 h 40 min = 09 40.",
   "hints": [
    "Find the total time: 8 cars $$\\times$$ 20 min each.",
    "160 min = 2 h 40 min; add this to 07 00."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q4",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (2) = 09 40."
  },
  {
   "n": 5,
   "type_id": 1,
   "question": "Jacob took 2 min 38 s to jog round a park. His sister took 40 s faster than him to complete the same distance. How long did his sister take?",
   "answer0": "1 min 20 s",
   "answer1": "1 min 58 s",
   "answer2": "2 min 2 s",
   "answer3": "2 min 78 s",
   "correct_answer": 1,
   "skill_id": 133,
   "difficulty_id": 2,
   "explanation": "Subtract 40 s from Jacob's time. 2 min 38 s = 158 s. 158 s - 40 s = 118 s = 1 min 58 s.",
   "hints": [
    "Convert 2 min 38 s into seconds: 2 $$\\times$$ 60 + 38 = 158 s.",
    "Subtract 40 s, then change back to minutes and seconds."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q5",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key: option (2) = 1 min 58 s."
  },
  {
   "n": 6,
   "type_id": 2,
   "question": "The Tan family arrived at the Singapore Zoological Gardens at 11.30 a.m. and left at 3.40 p.m. How long was their visit to the zoo?",
   "answer0": "4 h 10 min",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 93,
   "difficulty_id": 2,
   "explanation": "Find the duration from 11.30 a.m. to 3.40 p.m. From 11.30 a.m. to 3.30 p.m. is 4 h, then 3.30 p.m. to 3.40 p.m. is 10 min. Total = 4 h 10 min.",
   "hints": [
    "Count the whole hours from 11.30 a.m. to 3.30 p.m.",
    "Then add the extra minutes from 3.30 p.m. to 3.40 p.m."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q6",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 11.30am to 3.30pm = 4h; 3.30pm to 3.40pm = 10 mins. Ans: 4h 10min."
  },
  {
   "n": 7,
   "type_id": 2,
   "question": "A show started at 11.55 p.m. and ended 1 hour 45 minutes later. At what time did the show end?",
   "answer0": "1.40 a.m.",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 93,
   "difficulty_id": 2,
   "explanation": "Add 1 h 45 min to 11.55 p.m. 11.55 p.m. + 1 h = 12.55 a.m. Then 12.55 a.m. + 45 min = 1.40 a.m.",
   "hints": [
    "Add the hour first: 11.55 p.m. + 1 h = 12.55 a.m. (just past midnight).",
    "Then add 45 min to 12.55 a.m."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q7",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 11.55pm to 12.55pm = 1h; 12.55pm to 1.40am = 45 mins. Ans: 1.40am. (Key writes 12.55pm but crosses midnight to 1.40am.)"
  },
  {
   "n": 8,
   "type_id": 2,
   "question": "The MRT trains depart at intervals of 12 minutes. Find the time of departure of the fourth train if the first train departs at 7.45 p.m.",
   "answer0": "8.21 p.m.",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 93,
   "difficulty_id": 2,
   "explanation": "There are 3 intervals between the 1st and 4th trains. 3 $$\\times$$ 12 min = 36 min. 7.45 p.m. + 36 min = 8.21 p.m.",
   "hints": [
    "From the 1st to the 4th train there are 3 gaps, not 4.",
    "3 $$\\times$$ 12 min = 36 min; add this to 7.45 p.m."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q8",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key shows 7.45pm to 8.15pm = 30 mins, 8.15 to 8.20 = 5 mins, 8.20 to 8.21 = 1 min (total 36 min). Ans: 8.21pm."
  },
  {
   "n": 9,
   "type_id": 2,
   "question": "Victor exercises 4 times a week. He exercises 2 hours each time. How many weeks will Victor need to reach 200 hours of exercise?",
   "answer0": "25",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 118,
   "difficulty_id": 2,
   "explanation": "Hours per week = 4 $$\\times$$ 2 h = 8 h. Number of weeks = 200 h $$\\div$$ 8 h = 25 weeks.",
   "hints": [
    "First find how many hours Victor exercises in one week: 4 times $$\\times$$ 2 h.",
    "Divide the target 200 h by the weekly hours."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q9",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 4x2 = 8; 200 \\u00f7 8 = 25. Answer in weeks (25)."
  },
  {
   "n": 10,
   "type_id": 2,
   "question": "Cameron's watch shows the wrong time. When he left his house at 7.03 a.m., his watch showed the time as 7.15 a.m. Cameron has an appointment with the dentist at 9.45 a.m. When he arrived, his watch showed the time as 10.40 a.m. How many minutes late was he for his appointment?",
   "answer0": "43",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 93,
   "difficulty_id": 3,
   "explanation": "The watch is 12 min fast (7.15 - 7.03). When the watch showed 10.40 a.m., the real time was 10.40 - 12 min = 10.28 a.m. He was due at 9.45 a.m. Lateness = 9.45 a.m. to 10.40 a.m. on the watch = 55 min, minus the 12 min watch error = 43 min late. (9.45 to 10.40 = 55 min; 55 - 12 = 43 min.)",
   "hints": [
    "First find how fast the watch runs: 7.15 a.m. - 7.03 a.m. = 12 min fast.",
    "The watch-time gap from 9.45 to 10.40 is 55 min; subtract the 12 min error."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q10",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 9.45am to 10.00am = 15 mins, 10.00am to 10.40am = 40 mins, 40+15 = 55; 55 - 12 = 43 mins. Ans: 43 (minutes)."
  },
  {
   "n": 11,
   "type_id": 2,
   "question": "When it is 08 15 in Singapore, it is 09 15 in Seoul. Penny took a flight from Singapore to Seoul at 08 15 for a conference. The flight lasted 4 h 50 min. What time was it in Seoul when the flight landed?",
   "answer0": "1405",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 135,
   "difficulty_id": 3,
   "explanation": "Seoul is 1 h ahead of Singapore. Departure in Seoul time = 08 15 + 1 h = 09 15. Add the flight time: 09 15 + 4 h 50 min = 14 05. The flight landed at 1405 Seoul time.",
   "hints": [
    "Seoul is 1 hour ahead, so the departure is 09 15 in Seoul time.",
    "Add the flight duration of 4 h 50 min to 09 15."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q11",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 0815 to 1215 = 4h, 1215 to 1305 = 50 mins, 1305 to 1405 = 1h. Ans: 1405."
  },
  {
   "n": 12,
   "type_id": 2,
   "question": "When it is 10 00 in Country A, it is 08 40 in Singapore. Zacchaeus took a flight from Country A at 09 00 to Singapore. The flight lasted 3 h 29 min. What time was it in Singapore when the flight landed? Express your answer using the 24-hour clock.",
   "answer0": "1109",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 135,
   "difficulty_id": 3,
   "explanation": "Country A is 1 h 20 min ahead of Singapore (10 00 vs 08 40). Departure 09 00 in Country A = 09 00 - 1 h 20 min = 07 40 in Singapore time. Add the flight time: 07 40 + 3 h 29 min = 11 09. The flight landed at 1109.",
   "hints": [
    "Find the time difference: 10 00 - 08 40 = 1 h 20 min, with Country A ahead.",
    "Convert the 09 00 departure to Singapore time (07 40), then add 3 h 29 min."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q12",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 0900 to 1000 = 1h; 1000 to 0840 = 1h20mins; 1129 - 1h20 = ... 0740 + 3h29 = 1109. Ans: 1109."
  },
  {
   "n": 13,
   "type_id": 2,
   "question": "Two lighthouses flash their lights every 24 seconds and 60 seconds respectively. They flash together at 8.40 p.m. When is the next time the two lighthouses will flash their lights together again?",
   "answer0": "8.42 p.m.",
   "answer1": null,
   "answer2": null,
   "answer3": null,
   "correct_answer": null,
   "skill_id": 115,
   "difficulty_id": 3,
   "explanation": "Find the lowest common multiple of 24 and 60. Multiples of 24: 24, 48, 72, 96, 120; multiples of 60: 60, 120. LCM = 120 s = 2 min. So they flash together again 2 min after 8.40 p.m. = 8.42 p.m.",
   "hints": [
    "Find the LCM of 24 s and 60 s (the smallest time both divide into).",
    "120 s = 2 min; add this to 8.40 p.m."
   ],
   "source": "Raffles Girls 2022 P4 Weighted Assessment 1 Q13",
   "image_needed": false,
   "image_options": false,
   "image_file": null,
   "notes": "Key working: 24x5 = 120, 60x2 = 120, 2 mins = 120s; 8.40pm + 2 mins = 8.42pm. Ans: 8.42pm. (LCM / common multiple question, skill 115.)"
  }
 ]
}