Compute last week's total, this week's new individual amounts, then the percentage increase.<br><br>\\(\begin{aligned}<br>\text{Last week total} &= \$8 + \$6 = \$14<br>\\<br>\text{This week sandwich (25\% more)} &= \$8 \times 1.25 = \$10<br>\\<br>\text{This week juice (50\% more)} &= \$6 \times 1.50 = \$9<br>\\<br>\text{This week total} &= \$10 + \$9 = \$19<br>\\<br>\text{Increase} &= \$19 - \$14 = \$5<br>\\<br>\text{Percentage increase} &= \frac{5}{14} \times 100\% = 35\frac{5}{7}\%<br>\end{aligned}\\)<br><br>Final Answer: \\(35\frac{5}{7}\%\\) (approximately 35.71%)