Every spider has 8 compound eyes. How many eyes have 21 spiders?

A nail 4 inches long is driven through a board so that it projects 1.695 inches on one side and 1.428 on the other. How thick is the board?

Find the perimeter of an envelope 5 in. by 3¼ in.

How many minutes in 5⁄9 of 9⁄4 of an hour?

Mrs. Knox is 3⁄4 as old as Mr. Knox, who is 48 years old. Their son Edward is 4⁄9 as old as his mother. How old is Edward?

Suppose a pie to be exactly round and 10½ miles in diameter. If it were cut into 6 equal pieces, how long would the curved edge of each piece be?

81⁄3% of a class of 36 boys were absent on a rainy day. 331⁄3% of those present went out of the room to the school yard. How many were left in the room?

Just after a ton of hay was weighed in market, a horse ate one pound of it. What was the ratio of what he ate to what was left?

If a fan having 15 rays opens out so that the outer rays form a straight line, how many degrees are there between any two adjacent rays?

One half of the distance between St. Louis and New Orleans is 280 miles more than 1⁄10 of the distance; what is the distance between these places?