PSLE
Nora had two ribbons of the same length. She cut the first ribbon into equal parts of length 25 cm and to each part she tied 2 blue heart cutouts. After that, she cut the second ribbon into equal parts of length 40 cm and to each part she tied 4 silver heart cutouts. When she finished tying, she counted that there were 20 more silver heart cutouts than blue heart cutouts. How many heart cutouts were there altogether?

	First ribbon	Second ribbon	Difference	Total
Length of each part	25 cm	40 cm
Number of balloons tied to each part	2 blue balloons	4 silver balloons
LCM	200 cm	200 cm
Number of equal parts	200 ÷ 25 = 8	200 ÷ 40 = 5
Number of balloons for each ribbon per set	8 x 2 = 16	4 x 5 = 20	20 - 16 = 4	16 + 20 = 36

LCM of 25 and 40 = 200

Number of sets of 2 blue heart cutouts in a length of 200 cm
= 200 ÷ 25
= 8

Number of blue heart cutouts in a length of 200 cm
= 8 x 2
= 16

Number of sets of 4 silver heart cutouts in a length of 200 cm
= 200 ÷ 40
= 5

Number of silver heart cutouts in a length of 200 cm
= 5 x 4
= 20

Extra number of silver heart cutouts in a length of 200 cm
= 20 - 16
= 4

Number of sets of heart cutouts
= 20 ÷ 4
= 5

Total number of heart cutouts in one set of 200 cm of blue balloons and one set of 200 cm of silver balloons
= 16 + 20
= 36

Total number of heart cutouts of the two ribbons
= 5 x 36
= 180

Answer(s): 180