[Question]: John buys 500 newspapers. Each newspaper sells for $2. He sells 80% of them. He buys them all for 75% less than the price at which he sells them. How much profit does he make?
[Answer]: He sells 500 * .8 = 400 newspapers. He sells them for 400 * 2 = $800. He gets a discount of 2 * .75 = $1.5 on the newspapers. So he buys them for 2 - 1.5 = $.5. So he spent 500 * .5 = $250 buying them. That means he made a profit of 800 - 250 = $550.
So the answer is 550.

[Question]: There are 4,000 jelly beans in a jar. If three fourths of the jelly beans are red, and one quarter of the red jelly beans are coconut flavored, how many jelly beans are coconut flavored?
[Answer]: There are 4000 / 4 * 3 = 3000 red jelly beans. There are 3000 / 4 = 750 coconut flavored jelly beans.
So the answer is 750.

[Question]: Mark hires a singer for 3 hours at $15 an hour. He then tips the singer 20%. How much did he pay?
[Answer]:
The cost was 15 * 3 = $45. So the tip was 45 * .2 = $9. So in total, he paid 45 + 9 = $54.
So the answer is 54.