Question

Wally purchased a bag of marbles on Monday. On Tuesday he gave half of the marbles to his brother, James. On Wednesday he gave ten marbles to his sister. On Thursday he gave twenty marbles to his other sister. Wally had fifty marbles left. How many marbles did Wally purchase on Monday?

1) 90
2) 100
3) 120
4) 160

Answer 1

Wally purchased 140 marbles on Monday.

Step-by-step explanation:

To find out how many marbles Wally purchased on Monday, we need to work backwards from the information provided. We know that on Thursday he had 50 marbles left after giving away some on Wednesday, but we don't know how many he had before. We also know that on Wednesday he gave away 20 marbles, so on Tuesday he must have had 50+20 = 70 marbles. On Tuesday he gave away half of the marbles to his brother, which means he must have started with 70 x 2 = 140 marbles on Monday. Therefore, Wally purchased 140 marbles on Monday.