Price of sugar increased 25%. Expenditure to rise only 12%. Consumption reduced by: MCQ with Answer and Explanation

Explanation:
Let speed in still water = x, stream = y. 16/(x-y) + 24/(x+y) = 6; 12/(x-y) + 36/(x+y) = 6. Let 1/(x-y)=a, 1/(x+y)=b. 16a+24b=6, 12a+36b=6. Solving: a=1/4, b=1/12. So x-y=4, x+y=12 → x=8, y=4. Wait, x=8, not 10. I miscalculated: 16a+24b=6, divide by 2: 8a+12b=3. 12a+36b=6 → 2a+6b=1. From 2a+6b=1 → a=(1-6b)/2. Substitute: 8*(1-6b)/2 +12b = 4(1-6b)+12b = 4-24b+12b = 4-12b = 3 → b=1/12. Then a = (1-6/12)/2 = (1-0.5)/2 = 0.25 = 1/4. So x-y=4, x+y=12 → x=8. So answer 8 kmph. Option B 8 kmph. I'll correct options.

Explanation:
0.6 × 1.25 = 0.75, 25% decrease.

Explanation:
B = 0.75×8000=6000, A = 1.4×6000=8400.