Answer:
24. 40 minutes approximately
25. 8 days
Step-by-step explanation:
24. 40 minutes
Anna: 1 hour
Peter: 3 hours
Maria: 6 hours
A way to solve this kind of question is to think about how much they can perform given the same amount of time.
Anna: 1 hour x 6: 6 hours (In 6 hours Anna can clean 6 houses)
Peter: 3 hours x 2 6 hours (In 6 hours Peter can clean 2 houses)
Maria: 6 hours x 1: 6 hours (In 6 hours Peter can clean 1 house)
Working together they can clean the house 9 times faster.
It is 0.66 hours, or approximately 40 minutes
25. 8 days
It climbs 3 feet up but then it falls 2 feet down while sleeping during
the night. So the snail actually climbs 1 foot every day. It happens in the first 7 days. On the 8th day it goes out before sleep.
