The average age of an adult class is 40 years. 2 new students with an avg age of 32 years join the class. Therefore decreasing the average by 4 year. Find what was the original strength of class? Choose the correct choice from the following options.
A) 10 B) 12 C) 16 D) 2 E) 22

Rationale: "let original strength = y then , 40 y + 2 x 32 = ( y + 2 ) x 36 â ‡ ’ 40 y + 64 = 36 y + 72 â ‡ ’ 4 y = 8 â ˆ ´ y = 2 d"
Answer: D