PSLE
Esther had two ribbons of the same length. She cut the first ribbon into equal parts of length 30 cm and to each part she tied 2 grey stars. After that, she cut the second ribbon into equal parts of length 45 cm and to each part she tied 5 pink stars. When she finished tying, she counted that there were 8 more pink stars than grey stars. How many stars were there altogether?

	First ribbon	Second ribbon	Difference	Total
Length of each part	30 cm	45 cm
Number of balloons tied to each part	2 grey balloons	5 pink balloons
LCM	90 cm	90 cm
Number of equal parts	90 ÷ 30 = 3	90 ÷ 45 = 2
Number of balloons for each ribbon per set	3 x 2 = 6	5 x 2 = 10	10 - 6 = 4	6 + 10 = 16

LCM of 30 and 45 = 90

Number of sets of 2 grey stars in a length of 90 cm
= 90 ÷ 30
= 3

Number of grey stars in a length of 90 cm
= 3 x 2
= 6

Number of sets of 5 pink stars in a length of 90 cm
= 90 ÷ 45
= 2

Number of pink stars in a length of 90 cm
= 2 x 5
= 10

Extra number of pink stars in a length of 90 cm
= 10 - 6
= 4

Number of sets of stars
= 8 ÷ 4
= 2

Total number of stars in one set of 90 cm of grey balloons and one set of 90 cm of pink balloons
= 6 + 10
= 16

Total number of stars of the two ribbons
= 2 x 16
= 32

Answer(s): 32