{"27309":{"question":"The rate for parcel postage at a post office is: not over 100 g = \\$2.50; not over 250 g = \\$3.90; not over 500 g = \\$5.20; every additional 100 g = \\$1. Alice posted a parcel that weighed 660 g. How much did she pay for the postage? [?]","explanation":"660 g = first 500 g ($5.20) + 160 g above 500 g. 160 g counts as 2 additional 100-g steps = 2 x $1 = $2. Total = $5.20 + $2 = $7.20."},"27322":{"question":"The charges for water consumption are: Up to 40 m\u00b3 = 117 cents per m\u00b3; Above 40 m\u00b3 = 140 cents per m\u00b3.<br>(a) John's family used 32 m\u00b3 of water in March. How much did his family pay? \\$[?]<br>(b) Simon's family spent \\$66.40 on water consumption in April. How much water did his family use? Give your answer in m\u00b3. [?] m\u00b3","explanation":"(a) 32 m\u00b3 is within the first 40 m\u00b3, so charge = $1.17 x 32 = $37.44.<br>(b) First 40 m\u00b3 cost $1.17 x 40 = $46.80.<br>Remaining $66.40 - $46.80 = $19.60 charged at $1.40\/m\u00b3 -> 19.60 \u00f7 1.40 = 14 m\u00b3.<br>Total water = 40 + 14 = 54 m\u00b3."}}