The average age of a husband and wife was 23 years when they were married 5 years ago. The average age of the husband, the wife and a child who was born during the interval, is 20 years now. How old is the child now?
1). 9 months
2). 1 year
3). 3 years
4). 4 years
Let present ages of husband, wife and child be m, n and p years respectively.
Given,
⇒ [(m – 5) + (n – 5)]/ 2 = 23
⇒ m + n = 46 + 10 = 56
Given,
⇒ (m + n + p)/3 = 20
⇒ m + n + p = 60
⇒ 56 + p = 60
⇒ p = 4
∴ Child is 4 years old now.10. How many prime factors are there in the expression 1240 × 1448 × 254?