[Question]A hot air balloon with 200 balloons is blowing up. After about half an hour, 1/5 of the total number of balloons in the hot air balloon have blown up. After another hour, twice the number of balloons that had already blown up also blow up. How many balloons in the hot air balloon remain intact?
[Answer]After half an hour, the number of balloons that had blown up is 1 / 5 * 200 = 40. The number of balloons that haven't blown up so far is 200 - 40 = 160. In the next hour, 2 * 40 = 80 balloons blow up. The number of balloons that haven't blown up now is 160 - 80 = 80. The answer is 80.
Q: Beth had 150 students in her 10th-grade class. The following year 30 more students join. In her final year, 15 students left. How many students did Beth have in her class at the end of her final year?
A: Beth had 150 students her 10th - grade year, and added 30 more the following for a total of 150 + 30 = 180 students. In her final year, 15 students left her class, bringing her total to 180 - 15 = 165 students. The answer is 165.
Question: Carla is making smoothies. If she uses 500 ml of watermelon puree and 100 ml of cream, how many 150 ml servings can she make?
Answer: First find the total volume of the smoothie mix: 500 ml + 100 ml = 600 ml. Then divide the total volume by the volume per serving to find the number of servings: 600 ml / 150 ml / serving = 4 servings. The answer is 4.
[Question]A one-way ticket costs $2. A 30-day pass costs $50. What's the minimum number of rides you will need to take every month so that the 30-day pass is strictly cheaper per ride?
[Answer]For the 30 - day pass to be cheaper, then the average fare should be cheaper than the $2 one - way ticket. If the 30 - day pass costs $50, then I should take at least $50 / $2 = 25 rides to pay the same as a one - way ticket. However, given that we want the 30 - day pass per ride to be strictly cheaper we should ride at least 25 + 1 = 26 times. The answer is 26.
Q: In a jar that has 50 ants, the number of ants in the jar doubles each hour. How many ants will be in the jar after 5 hours?
A: After first hour, 50 * 2 = 100 ants. After the second hour, 100 * 2 = 200 ants. After the third hour, 200 * 2 = 400 ants. After the fourth hour, 400 * 2 = 800 ants. After the fifth hour, 800 * 2 = 1600 ants. The answer is 1600.
Question: Sandy earns $15 per hour. She worked 10 hours on Friday with her best friend, 6 hours on Saturday alone and 14 hours on Sunday with her other co-workers. How much money did Sandy earn in all on Friday, Saturday and Sunday?
Answer:
The total number of hours Sandy worked on Friday, Saturday and Sunday was 10 + 6 + 14 = 30 hours. Beth made 30 × $15 = $450 in those 3 days. The answer is 450.