Multiple choice

Two vessel contain petrol and kerosene in the ratio 7 : 3 and 1 : 4. In what ratio should both vessel is mixed so that the mixture contain petrol and kerosene in the ratio 3 : 2?

  1. 4 : 1

  2. 1 : 4

  3. 2 : 3

  4. 3 : 2

  5. None of these

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

Let x litres from first vessel (7:3 = 70% petrol) and y litres from second vessel (1:4 = 20% petrol). Target ratio 3:2 means 60% petrol. Using alligation: (70-60):(60-20) = 10:40 = 1:4. So x:y = 4:1 (4 parts from first vessel, 1 part from second vessel). Verify: 4×0.7 + 1×0.2 = 3.0 petrol; 4×0.3 + 1×0.4 = 1.6 petrol+1.6=4.6, ratio 3.0:2.0 = 3:2 ✓