Question

Of the 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. $45$
• C. $48$
• D. $60.25$

Answer 1

The correct option is A $15$

Let the first number be x

According to the question

Sum of four numbers $=x+4x=5x$

As first number x is one fourth of the sum of the last three 4x

So,

$\frac{5x}{4}=60$

$5x=240$

$x=48$

Therefore the first number is 48.