Maths Problem Sums (Factors and Multiples)

1. Alan wants to cover a cardboard measuring 80 cm by 100 cm with square coloured paper of the same size. He uses only whole square coloured paper.
(a) Find the largest possible length of the side of each square coloured paper.
(b) Find the number of such square coloured paper that Alan needs to cover the cardboard.

2. Jonathon bought an item that was less than $100. He could pay for the item exactly with only $2 notes. He could also pay for the item exactly with $5 notes. What were the likely prices of the item he bought?

3. Mark cycles in Punggol Park once every 4 days while Lee Hua cycles there once every 5 days and Priya cycles there once every 10 days. If they cycled there together on 3 July, on what date would they cycle together at Punggol Park?

4. Michelle prepared a mixture of apple, carrot and celery juices. 1/3 of the mixture was apple juice and 2/5 of the remainder was celery juice. 315ml of the mixture was celery juice. What volume of the mixture was carrot juice?

5. 6A and 6B have the same number of pupils each. 1/4 of all the boys are from 6A and 1/5 of all the girls are from 6B. What is the ratio of the number of girls to the number of boys in 6B?

6. Alan invited his classmates to his birthday party. He invited 20 more boys than girls. 3/4 of the boys and 2/3 of the firls attended the party and 19 children did not attend the party. How many children were invited?

7. PSLE Booklet, P17 Qn 54, Balloon Question