[Question]Johnny is an engineer designing a bridge. The roadway deck for the top of the bridge needs 1600 tons of concrete to construct. The two bridge anchors need equal amounts of concrete, but only one has been built so far, using 700 tons of concrete. Johnny had to calculate how many tons of concrete the supporting pillars underneath the bridge would need, and he found that the total amount of concrete in the entire bridge will be 4800 tons. How much concrete did Johnny find he needs for the supporting pillars?
[Answer]The bridge anchors will take 700 * 2 = 1400 tons of concrete. The roadway deck and bridge anchors need 1600 + 1400 = 3000 tons of concrete. Thus, Johnny found the supporting pillars need 4800 - 3000 = 1800 tons of concrete. The answer is 1800.
Q: A man drives 60 mph for 3 hours. How fast would he have to drive over the next 2 hours to get an average speed of 70 mph?
A: To have an average speed of 70 mph over 5 hours he needs to travel 70 * 5 = 350 miles. He drove 60 * 3 = 180 miles in the first 3 hours. He needs to travel another 350 - 180 = 170 miles over the next 2 hours. His speed needs to be 170 / 2 = 85 mph. The answer is 85.
Question: Two runners are competing in a 10-mile race. The first runs at an average pace of 8 minutes per mile, while the second runs at an average pace of 7 minutes per mile. After 56 minutes, the second runner stops for a drink of water. For how many minutes could the second runner remain stopped before the first runner catches up with him?
Answer: After 56 minutes, the second runner has traveled 56 / 7 = 8 miles. Similarly, the first runner has traveled 56 / 8 = 7 miles. Therefore, the two runners are 8 - 7 = 1 mile apart when the second runner stops. Thus, the second runner can stop for a maximum of 8 minutes, which is the amount of time it takes the first runner to travel 1 mile. The answer is 8.
[Question]Brendan went fishing with his dad. Brenden caught 8 fish in the morning. He threw 3 back that were too small. He caught 5 more in the afternoon. Brendan's dad caught 13 fish. How many fish did they catch in all?
[Answer]Brenden caught 8 fish in the morning + 5 in the afternoon = 13 fish. After throwing the small fish back, Brenden has 13 3 = 10 fish. Together, Brenden and his dad caught 10 + 13 = 23 fish. The answer is 23.
Q: Tim has to go to the doctor for a sporting injury. He gets an MRI which costs $1200. The doctor needs to examine it for 30 minutes and charges $300 per hour. There is also a $150 fee just for being seen. Insurance covered 80% how much did he pay?
A: The doctor charged 300 / 2 = $150. So the total cost was 150 + 150 + 1200 = $1500. The insurance covered 1500 * .8 = $1200. So he paid 1500 - 1200 = $300. The answer is 300.
Question: Last night, Olive charged her phone for 10 hours. Assuming each hour of charge lasts the phone 2 hours of use, calculate the total time Olive would be able to use her phone before it goes off if she charges it for 3/5 of the time she charged the phone last night.
Answer:
If Olive charges her phone for 3 / 5 of the time she charged the phone last night, the phone would be charged for 3 / 5 * 10 = 6 hours. Assuming each hour of charge lasts the phone 2 hours of use, the phone will last for 6 * 2 = 12 hours before it goes off when Olive uses it on a six hours charge. The answer is 12.