The average of 5 numbers is 26.4. The first number is one-fifth of the sum of the remaining 4 numbers. What is the first number?

22

Sum of 5 numbers = 5 × 26.4 = 132

ATQ,

First number = \(\frac{1}{5}\) × ( Sum of Other 4 number )

Sum of other 4 number = 5 × First number

First number + 5 × First number = 132

6 × First number= 132

First number = 22