Q: There are 45 children in a classroom. One-third of them are girls. How many boys are in the classroom?
A: One - third of all the kids are girls, which means 1 / 3 * 45 = 15 children. So there are 45 - 15 = 30 boys in the classroom. The answer is 30.
Question: In four years, Peter will be twice as old as Harriet. If Peter's age is currently half of his mother's age, who is 60, how old is Harriet now?
Answer: If Peter's age is currently half of his mother's age, who is 60, Peter is 1 / 2 * 60 = 30 years old. In four years, Peter will be 30 + 4 = 34 years old. Since Peter's age in four years will be twice Harriet's age, Harriet will be 34 / 2 = 17 years old in four years. Currently, Harriet is 17 - 4 = 13 years old. The answer is 13.
[Question]Juniper, the Irish Setter, has 4 bones. Her master gives her enough bones to double her number of bones. Unfortunately, the neighbor's dog steals away two of Juniper's bones. How many bones does Juniper have remaining?
[Answer]Doubling 4 bones gives her 4 * 2 = 8 bones. The neighbor's dog steals two bones, leaving 8 - 2 = 6 bones. The answer is 6.
Q: Leila spent 3/4 of her savings on make-up and the rest on a sweater. If the sweater cost her $20, what were her original savings?
A: If Leila spent 3 / 4 of her savings on make - up, this means she spent 1 - 3 / 4 = 1 / 4 of her savings on a sweater. Let S be her original savings. If the sweater cost $20, this means 1 / 4 * S = $20. Thus S = $20 * 4 = $80. The answer is 80.
Question: Polly and Gerald went for a fun afternoon riding mini race cars at the munchkin track, which is a one-quarter mile circular track. Polly managed to circle the track 12 times in one half hour, but Gerald's car was malfunctioning, and he only moved at an average speed half of what Polly did. What speed did Gerald's car average, in miles per hour?
Answer: Polly circled the one - quarter mile track 12 times in 0.5 hours at a speed of 12 / 0.5 = 24 circuits of the track per hour. 24 / 4 = 6 miles per hour. Gerald traveled at a speed half of what Polly traveled for an average speed of 6 / 2 = 3 miles per hour. The answer is 3.
Q: Every 10 seconds, there is a car collision, and every 20 seconds there is a big crash. How many accidents overall will happen in 4 minutes?
A:
1 minute is 60 seconds, so 4 minutes is 4 * 60 = 240 seconds. During this time there would be 240 / 20 = 12 big crashes. And also 240 / 10 = 24 car collisions. So in total during 4 minutes there would be 12 + 24 = 36 accidents. The answer is 36.