Multiple choice

The ratio of the ages of two brothers Simba and Pumbaa in year 2018 is 7 : 5; and 8 years ago, the ratio of their ages was 5 : 3, respectively. Find the average of their ages in year 2020.

  1. 20 years

  2. 22 years

  3. 24 years

  4. 26 years

  5. 28 years

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

Let ages in 2018 be 7x and 5x. 8 years ago (2010), ages were 7x-8 and 5x-8. Ratio (7x-8)/(5x-8) = 5/3. 21x - 24 = 25x - 40. 4x = 16, so x = 4. Ages in 2018: 28 and 20. Ages in 2020: 30 and 22. Average = (30+22)/2 = 26.

AI explanation

In 2018, let Simba's age be 7x and Pumbaa's age be 5x. Eight years ago in 2010, their ages were 7x - 8 and 5x - 8, so the equation is (7x - 8) / (5x - 8) = 5 / 3. Cross-multiplying gives 21x - 24 = 25x - 40, meaning 4x = 16 and x = 4. In 2018 their ages were 28 and 20, so in 2020 they are 32 and 24, which averages to 26 years.