The average of 4 terms is 30 and the 1st term is $\frac{1}{3}$ of the sum of the remaining terms. What is the first term ?

60 30 40 20

30

Lets assume sum of last three terms be 3x 1st term = 3x × \(\frac{1}{3}\) = x Sum of 4 terms = 120 x + 3x = 120 x = 30