The answer is; 24/75 of the entire cake remained
If 2/5 of the initial cake was eaten, the 3/5 is what remained
MInu ate 1/3 of the 3/5 = 3/15
3/5 – 3/15 = 6/15 remained
Her brother ate; 1/5 of 6/15 = 6/75
6/15 – 6/75 = 24/75 remained
Given:
m∠NRQ = 60°
To find:
The angle measure of minor arc NQ
Solution:
The inscribed angle is half of the intercepted arc.

Multiply by 2 on both sides.


Substitute m∠NRQ = 60°.


The measure of minor arc NQ is 120°.
Area = side * side
Area of the square = 6 1/9 * 6/1/9
= 36 1/81