We have a question: Billy ate 20 apples this week. On Monday, he ate 2 apples. On Tuesday, he ate twice as many as he ate the day before. He’s not sure what he ate on Wednesday. On Thursday, he ate four times as many as he ate on Friday. On Friday, he ate half of the amount he ate on Monday. How many apples did he eat on Wednesday?
And an answer: 9
So how you got the answer?
On Tuesday, Billy ate 2 * 2 = 4 apples. On Friday, he ate 2 * 0.5 = 1 apple. On Thursday, he ate 4 * 1 = 4 apples. So for Monday, Tuesday, Thursday, and Friday, Billy ate a total of 2 + 4 + 4 + 1 = 11 apples. This means that on Wednesday, he must have eaten 20 – 11 = 9 apples.

We have a question: Colbert is building a treehouse out of wooden planks. The treehouse needs 200 wooden planks. A quarter of these planks come from Colbert’s storage, half of these planks come from Colbert’s parents, 20 planks come from Colbert’s friends and he buys the rest from the store. How many planks of wood does he need to buy from the store to finish his treehouse?
And an answer: 30
So how you got the answer?
In Colbert’s storage, there are 200 wooden planks / 4 = 50 wooden planks. From his parents, there are 200 wooden planks / 2 = 100 wooden planks. So in total, Colbert has not had to buy 50 wooden planks from storage + 100 wooden planks from his parents + 20 wooden planks from his friends = 170 wooden planks. He therefore still needs to buy 200 needed wooden planks – 170 owned wooden planks = 30 wooden planks.

We have a question: Jar A has 28 marbles. Jar B has 12 more marbles than jar A. Jar C has twice as many marbles as jar B. How many marbles are there altogether?
And an answer: 148
So how you got the answer?
Jar B has 28 + 12 = 40 marbles. Jar C has 2 x 40 = 80 marbles. Therefore, there are 28 + 40 + 80 = 148 marbles altogether.