Question

The average of 4 terms is 20 and the 1st term is 1/3 of the remaining terms. What will be the first number?

Answer 1

Average of $4$ terms $=20$
Hence, the total sum of $4$ terms $=80$
Let terms be $A,B,C,D$
So, the sum will be $A+B+C+D=80$
Given, $3A=B+C+D$
So, $4A=80,$
$A=20$