Level 2
The distance between Jenny's home and the bookstore is 500 m. After walking a distance from her home to the bookstore, she stopped and walked 90 m back to a pet shop. If the pet shop is 150 m away from her home, how far had she walked before she stopped and walked back?
Level 3
A coin bank contains some twenty-cent and fifty-cent coins in the ratio of 2 : 5.
When 10 fifty-cent coins are taken out and exchanged with some twenty-cent coins of the same value,
the ratio became 8 : 9.
Find the sum of money in the coin box in dollars.
Level 2
Priscilla has more than 20 pencils but fewer than 40 pencils The pencils can be packed into bags of 4 pencils without any remainder. The pencils can also be packed into bags of 6 pencils without any remainder. What is the most number of pencils that Priscilla has?