The average age of women and child workers in a factory was 15 yr. The average age of all the 16 children was 8 yr and average age of women workers was 22 yr. If 10 women workers were married, then the number of unmarried women workers was.

Correct Answer: 6

Explanation:

Let the number of women workers be Y.
Then, 22y + 16 x 8 = 15 (16+y)
⇒ 22y + 128 = 240 + 15y
⇒ 22y - 15y= 240 - 128
∴ y = 16
∴ Unmarried women workers = 16 - 10 = 6