Multiple choice

A mixture is made by mixing alcohol and water in the ratio (13 ∶ 7). If (3m) litres of alcohol and (5m) litres of water is mixed in 120 litres of mixture, the new ratio becomes (15 ∶ 17). Find the quantity of the new mixture.

  1. 289 litres

  2. 352 litres

  3. 316 litres

  4. 297 litres

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Initial 120L mixture has 78L alcohol and 42L water (13:7 ratio). After adding 3m alcohol + 5m water, new ratio (78+3m)/(42+5m) = 15/17. Cross-multiply: 17(78+3m) = 15(42+5m), giving 1326+51m = 630+75m, so 24m=696, m=29. Total new mixture = 120+3(29)+5(29) = 352L.