Question

24.) In a junior cricket team, ages of boys are in AP., the common difference being 3
months. The youngest boy is 7 years old and sum of the ages of all those boys
​

Answer 1

The ages of the boys are in A.P.

d=3

a=7

There are 11 players in a cricket team.

n=11

$Sn = \frac{n}{2}2a + (n - 1)d$

$S11 = \frac{11}{2} 2(7) + (11 - 1)3$

$S11 = \frac{11}{2} 14 + 30$

$S11 = \frac{11}{2} (44)$

$S11 = 11(22)$

$S11 = 242$

Sum of the ages of all the boys is 242.

Answer 2

25

Explanation:

Given, d = 3 months; a = 7 years or 84 months; Sn = 250 years or 3000 months

We know, Sn = n/2 [ 2a + ( n-1 )d ]

Substituting we get,

3000 = n/2 [ 2×84 + ( n-1 )3 ]

n^2 + 85n - 2000 = 0

Therefore n = 25 ( negative values not accepted )