PSLE
Xylium had two streamers of the same length. She cut the first streamer into equal parts of length 15 cm and to each part she tied 2 silver balloons. After that, she cut the second streamer into equal parts of length 25 cm and to each part she tied 4 grey balloons. When she finished tying, she counted that there were 8 more grey balloons than silver balloons. How many balloons were there altogether?

	First streamer	Second streamer	Difference	Total
Length of each part	15 cm	25 cm
Number of balloons tied to each part	2 silver balloons	4 grey balloons
LCM	75 cm	75 cm
Number of equal parts	75 ÷ 15 = 5	75 ÷ 25 = 3
Number of balloons for each streamer per set	5 x 2 = 10	4 x 3 = 12	12 - 10 = 2	10 + 12 = 22

LCM of 15 and 25 = 75

Number of sets of 2 silver balloons in a length of 75 cm
= 75 ÷ 15
= 5

Number of silver balloons in a length of 75 cm
= 5 x 2
= 10

Number of sets of 4 grey balloons in a length of 75 cm
= 75 ÷ 25
= 3

Number of grey balloons in a length of 75 cm
= 3 x 4
= 12

Extra number of grey balloons in a length of 75 cm
= 12 - 10
= 2

Number of sets of balloons
= 8 ÷ 2
= 4

Total number of balloons in one set of 75 cm of silver balloons and one set of 75 cm of grey balloons
= 10 + 12
= 22

Total number of balloons of the two streamers
= 4 x 22
= 88

Answer(s): 88