CMAT 2015 Solved Question Paper

(d) Let these is x workers present initially.
Average age of x workers = 42 yr
Total age of x workers =42x yr
Average age of 8 new workers = 36 yr
Total age of 8 new workers = 36 x 8 = 288 yr
Now, according to the question,

42x+288

x+8

= 40
⇒42x + 288 = 40(x+ 8)
⇒ 42x - 40x = 40 x 8 -288
⇒ 2x = 32
∴ x =

32

2

= 16
Hence, initially these are 16 workers.