Simplify.

1/3 (1-1/4) ^2

First step is parentheses so subtract 1/4 from 1

(1-1/4) = (4/4 - 1/4) = (3/4)

After parentheses we perform exponent operations

(3/4) ^2 = (3^2/4^2) = (9/16)

Finally, after exponent operations we perform multiplications

(1/3) * (9/16) = (3/16)