PSLE
Zara had two streamers of the same length. She cut the first streamer into equal parts of length 40 cm and to each part she tied 2 silver balls. After that, she cut the second streamer into equal parts of length 50 cm and to each part she tied 4 gold balls. When she finished tying, she counted that there were 12 more gold balls than silver balls. How many balls were there altogether?

	First streamer	Second streamer	Difference	Total
Length of each part	40 cm	50 cm
Number of balloons tied to each part	2 silver balloons	4 gold balloons
LCM	200 cm	200 cm
Number of equal parts	200 ÷ 40 = 5	200 ÷ 50 = 4
Number of balloons for each streamer per set	5 x 2 = 10	4 x 4 = 16	16 - 10 = 6	10 + 16 = 26

LCM of 40 and 50 = 200

Number of sets of 2 silver balls in a length of 200 cm
= 200 ÷ 40
= 5

Number of silver balls in a length of 200 cm
= 5 x 2
= 10

Number of sets of 4 gold balls in a length of 200 cm
= 200 ÷ 50
= 4

Number of gold balls in a length of 200 cm
= 4 x 4
= 16

Extra number of gold balls in a length of 200 cm
= 16 - 10
= 6

Number of sets of balls
= 12 ÷ 6
= 2

Total number of balls in one set of 200 cm of silver balloons and one set of 200 cm of gold balloons
= 10 + 16
= 26

Total number of balls of the two streamers
= 2 x 26
= 52

Answer(s): 52