In a class, three fifths of the children are girls. what percentage are boys.

40%

Step-by-step explanation:

If 3/5 =.06 are girls

that means

2/5 =.04 are boys

now

5/5 = 1 are the total children

Finally find the percentage

(.06) (100) = 60% girls

(.04) (100) = 40% boys