[Question]Bethany is working at the front desk at Joe’s Gym. There were some people lifting weights when she started her shift. Then 5 more people came in and started running on the treadmill and 2 people left. There are now 19 people in the gym. How many people were lifting weights at the start of Bethany’s shift?
[Answer]We know that 5 people came in and 2 people left after Bethany’s shift started, so there was a net change of 5 – 2 = 3 people. If there are 19 people now in the gym and that is 3 more than when Bethany’s shift started, we know there were 19 – 3 = 16 people lifting weights at the start of her shift. The answer is 16.
Q: Jamir and his two friends Sarah and Julien, go to their school's swimming pool to swim. Jamir swims 20 more meters per day than Sarah, who swims twice the distance Julien swims. They go to the swimming pool the whole week, swimming the same distances as before. If Julien swam 50 meters, what's the combined distance for three of them for the whole week?
A: If Julien swam for the whole week, then the total distance in meters that he covered is 50 * 7 = 350 meters. Sarah swam twice the distance covered by Julien, which is 2 * 50 = 100 meters. Sarah's total for the whole week is 100 * 7 = 700 meters. If Jamir swam 20 meters more than Sarah, he covered 100 + 20 = 120 meters. Jamir's total for the whole week is 120 * 7 = 840 meters. The combined distance for all of them is 840 + 700 + 350 = 1890 meters. The answer is 1890.
Question: In a fundraiser car wash activity, the 5th graders raised $147 on Friday. On Saturday, they made $7 more than twice their Friday earnings. Their earnings on Sunday are $78 more than their earnings on Friday. How much did they earn in three days?
Answer: Twice their Friday's earnings is $147 x 2 = $294. So, their Saturday earnings was $294 + $7 = $301. Their Sunday earnings was $147 + $78 = $225. Therefore, their total earnings in three days was $147 + $301 + $225 = $673. The answer is 673.
[Question]Very early this morning, Elise left home in a cab headed for the hospital. Fortunately, the roads were clear, and the cab company only charged her a base price of $3, and $4 for every mile she traveled. If Elise paid a total of $23, how far is the hospital from her house?
[Answer]For the distance she traveled, Elise paid 23 - 3 = 20 dollars. Since the cost per mile is $4, the distance from Elise’s house to the hospital is 20 / 4 = 5 miles. The answer is 5.
Q: A baker sells pastries for $5 and works 7 days a week. On Monday he sold 2. Every day the number of sales increases by 1 compared to the previous day. On average, how many pastries does he sell on each day of the week?
A: You know from the statement that on Monday he sells 2 pastries, so on Tuesday he sells 3, Wednesday 4, Thursday 5, Friday 6, Saturday 7 and Sunday 8 pastries. So the average value is (2 + 3 + 4 + 5 + 6 + 7 + 8) pastries / 7 days. The baker sells, on average, 35 / 7 = 5 pastries / day for 1 week. The answer is 5.
Question: A mosquito sucks 20 drops of blood every time it feeds on someone. If there are 5000 drops per liter and you have to lose 3 liters of blood to die, how many mosquitoes would have to feed on you to kill you?
Answer:
First find the total number of liters a mosquito sucks in one feeding: 20 drops / 5000 drops / liter = .004 L / feeding. Then divide the lethal amount of blood by the amount of blood one mosquito can drain: 3 L / .004 L / feeding = 750 feedings. The answer is 750.