Multiple choice

The present ages of two persons are 36 and 50 yr, respectively. If after (n) yr the ratio of their ages will be 3 : 4, then what is the value of (n) ?

  1. 5

  2. 7

  3. 6

  4. 8

  5. none of these

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

After n years, ages will be (36+n) and (50+n). The ratio is 3:4, so (36+n)/(50+n) = 3/4. Cross-multiplying: 4(36+n) = 3(50+n). This gives 144 + 4n = 150 + 3n, so n = 6. Verify: ages after 6 years are 42 and 56, and 42:56 simplifies to 3:4.