The average age of an adult class is 40 years. 12 new students with an average age of 32 years join the class. Therefore decreasing the average by 4 year. what was the original strength of class?
Correct Answer: 12
Explanation:
Let original strength = y
Then , 40y + 12 x 32 = ( y + 12) x 36
⇒ 40y + 384 = 36y + 432
⇒ 4y = 48
∴ y = 12
