We have a question: It takes John 13 seconds to run 100 meters. He only goes 4 meters in the first second. He then maintains the same speed for the rest of the race. James is 2 m/s faster at the top speed and he can run the first 10 meters in 2 seconds. How long does it take James to run 100 meters?
And an answer: 11
So how you got the answer?
John runs 100 - 4 = 96 meters once he reaches his max speed. He runs it in 13 - 1 = 12 seconds. So he runs at a speed of 96 / 12 = 8 m / s. So that means James's top speed is 8 + 2 = 10 m / s. He has to run 100 - 10 = 90 meters at his top speed. So he runs that at 90 / 10 = 9 seconds. So he takes 9 + 2 = 11 seconds to run 100 meters.

We have a question: John buys 20 candy bars. His brother Dave pays for 6 of them. If each candy bar costs $1.50, how much did John pay?
And an answer: 21
So how you got the answer?
He paid for 20 - 6 = 14 candy bars. So he paid 14 * 1.5 = $21.

We have a question: Nadia was sent to the flower shop to buy 20 roses and 3/4 times as many Lillies as roses. If roses cost $5 each and lilies cost twice as much each, calculate the total amount of money Nadia used to buy the flowers.
And an answer: 250
So how you got the answer?
The total cost for roses is 20 * 5 = $100. Nadia bought 3 / 4 * 20 = 15 lilies. Each lily costs 5 * 2 = $10. She used 10 * 15 = $150 in total to buy lilies. To buy all the flowers, Nadia used 150 + 100 = $250.