PSLE
Tiffany had two strings of the same length. She cut the first string into equal parts of length 40 cm and to each part she tied 2 white cartoon cutouts. After that, she cut the second string into equal parts of length 50 cm and to each part she tied 5 green cartoon cutouts. When she finished tying, she counted that there were 40 more green cartoon cutouts than white cartoon cutouts. How many cartoon cutouts were there altogether?

	First string	Second string	Difference	Total
Length of each part	40 cm	50 cm
Number of balloons tied to each part	2 white balloons	5 green balloons
LCM	200 cm	200 cm
Number of equal parts	200 ÷ 40 = 5	200 ÷ 50 = 4
Number of balloons for each string per set	5 x 2 = 10	5 x 4 = 20	20 - 10 = 10	10 + 20 = 30

LCM of 40 and 50 = 200

Number of sets of 2 white cartoon cutouts in a length of 200 cm
= 200 ÷ 40
= 5

Number of white cartoon cutouts in a length of 200 cm
= 5 x 2
= 10

Number of sets of 5 green cartoon cutouts in a length of 200 cm
= 200 ÷ 50
= 4

Number of green cartoon cutouts in a length of 200 cm
= 4 x 5
= 20

Extra number of green cartoon cutouts in a length of 200 cm
= 20 - 10
= 10

Number of sets of cartoon cutouts
= 40 ÷ 10
= 4

Total number of cartoon cutouts in one set of 200 cm of white balloons and one set of 200 cm of green balloons
= 10 + 20
= 30

Total number of cartoon cutouts of the two strings
= 4 x 30
= 120

Answer(s): 120