In 60 L of milk-water mixture, water is 10%. How much water must be added to make water 25%? MCQ with Answer and Explanation

Explanation:
Original x, xy=120. New 0.8x(y+5)=120 → 0.8×120 + 4x =120 → 96+4x=120 → 4x=24 → x=6, reduced 4.8? Wait: original x=6, reduced price = 0.8*6=4.8, option C. Check: original 6 per kg, 20 kg for 120. Reduced 4.8, buys 25 kg for 120, 5 kg more. So reduced price = 4.8. Option C. So answer C.

Explanation:
Food 40%, left 60%. Rent 30% of 60% = 18% of income. Total spend = 58%, save 42% = 3780 → income = 3780/0.42 = 9000.

Explanation:
1.15x = 138 → x = 120.