PSLE
Nicole had two ribbons of the same length. She cut the first ribbon into equal parts of length 90 cm and to each part she tied 2 red paper cranes. After that, she cut the second ribbon into equal parts of length 100 cm and to each part she tied 3 grey paper cranes. When she finished tying, she counted that there were 35 more grey paper cranes than red paper cranes. How many paper cranes were there altogether?

	First ribbon	Second ribbon	Difference	Total
Length of each part	90 cm	100 cm
Number of balloons tied to each part	2 red balloons	3 grey balloons
LCM	900 cm	900 cm
Number of equal parts	900 ÷ 90 = 10	900 ÷ 100 = 9
Number of balloons for each ribbon per set	10 x 2 = 20	3 x 9 = 27	27 - 20 = 7	20 + 27 = 47

LCM of 90 and 100 = 900

Number of sets of 2 red paper cranes in a length of 900 cm
= 900 ÷ 90
= 10

Number of red paper cranes in a length of 900 cm
= 10 x 2
= 20

Number of sets of 3 grey paper cranes in a length of 900 cm
= 900 ÷ 100
= 9

Number of grey paper cranes in a length of 900 cm
= 9 x 3
= 27

Extra number of grey paper cranes in a length of 900 cm
= 27 - 20
= 7

Number of sets of paper cranes
= 35 ÷ 7
= 5

Total number of paper cranes in one set of 900 cm of red balloons and one set of 900 cm of grey balloons
= 20 + 27
= 47

Total number of paper cranes of the two ribbons
= 5 x 47
= 235

Answer(s): 235