Average of three numbers is 60. First number is one fourth of the sum of the all numbers. The first number is:

30 36 42 45

45

Let the three numbers are = x, y, z ATQ,  ⇒ \(x\) = \(\frac{1}{4}\) (x+y+z) ⇒ x + y + z = 4x    --------- (i) Average of three no. = 60 ⇒ \(\frac{x+y+z}{3}\) = 60 From eqn (i)  ⇒ \(\frac{4x}{3}\) = 60 ⇒ x = 45