Question

cm 84. A father's age was three times and two times of his son at 2040 and 2050 respectively. What will be the birth year of son? a. 2030 b. 2035 c. 2031 d. 2032 100​

Answer 1

(a)2030

Explanation:

I'm assuming the 100 at the end of the question is a typo.
In 2040, the son's age can be written as
`(x)/(3)`, where x equals the age of his father. In 2050, the son's age can be written as
`(x-10)/(2)` (as ten years is added between 2040 and 2050). When equated to each other-->
`(x-10)/(2)` =
`(x)/(3)`, we can first simplify by multiplying both sides to reach the least common denomination 6, giving us 3(x-10)=2x --->3x-30=2x--->x=30 is the dad's age. The son's age in 2040, 30/3, is equal to 10 years, meaning he was born in the year 2030 (a).