Of four numbers whose average is 60, the first is one-fourth of the sum of the last three. The first number is -

A. 15

B. 42

C. 45

D. 48

Answer: Option D

Solution(By Examveda Team)

Let the four numbers be a, b, c and d respectively
Then,
⇒ a = $$\frac{1}{4}$$ (b + c + d)
⇒ b + c + d = 4a
Also,
a + b + c + d = 60 × 4 = 240
⇒ a + 4a = 240
⇒ 5a = 240
⇒ a = 48
Hence, first number = 48