We have a question: Lyle wants to buy himself and his friends a sandwich and a pack of juice. A sandwich costs $0.30 while a pack of juice costs $0.2. If Lyle has $2.50, how many of his friends can have a sandwich and a pack of juice?
And an answer: 4
So how you got the answer?
A sandwich and a pack of juice cost $0.3 + $0.2 = $0.50. With Lyle's $2.50, he can buy $2.50 / $0.50 = 5 sets of sandwiches and juice. Therefore, 5 - 1 = 4 of his friends can have a sandwich and a pack of juice since the other 1 set is for Lyle himself.

We have a question: Tom attends a party that collects $2000. Half the school attended and the school had 400 people. How much would they have made if 300 people attended?
And an answer: 3000
So how you got the answer?
There were 400 / 2 = 200 people in attendance. So that means each person paid 2000 / 200 = $10. So if 300 people attended they would have made 300 * 10 = $3000.

We have a question: It is recommended that men should consume no more than 150 calories of added sugar per day. Mark took a soft drink in the afternoon that contained 2500 calories, 5% of which was from added sugar. Then he bought some bars of candy which had 25 calories of added sugar each. If he eventually exceeded the recommended intake of added sugar by 100%, how many bars of candy did he take?
And an answer: 7
So how you got the answer?
He consumed 2500 calories, 5% of which is added sugar to give 2500 * (5 / 100) = 125 calories of added sugar. He exceeded the recommended intake of 150 calories by 100% for a total consumption of 150 + (150(100 / 100)) = $300. This means he took in 300 - 125 = 175 calories from candy alone. Each candy had 25 calories so 175 calories which means he consumed 175 / 25 = 7 bars?.