What is the answer to this equation??

The circumference of a circle is 5 pi cm. what is the area of the circle?

Mr. thompson took five of his children to the bowling alley the cost for children 12 and older is 350 the cost of four children under 12 inch to 25 he spent a total of 1625 how many of his children are 12 and order

From a group of 10 men and 8 women, 5 people are to be selected for a committee so that at least 4 men are on the committee. howmany ways can it be done?