PSLEMin had two ribbons of the same length. She cut the first ribbon into equal parts of length 50 cm and to each part she tied 3 white balls. After that, she cut the second ribbon into equal parts of length 70 cm and to each part she tied 5 brown balls. When she finished tying, she counted that there were 12 more brown balls than white balls. How many balls were there altogether?
|
First ribbon |
Second ribbon |
Difference |
Total |
Length of each part |
50 cm |
70 cm |
|
|
Number of balloons tied to each part |
3 white balloons |
5 brown balloons |
|
|
LCM |
350 cm |
350 cm |
|
|
Number of equal parts |
350 ÷ 50 = 7 |
350 ÷ 70 = 5 |
|
|
Number of balloons for each ribbon per set |
7 x 3 = 21 |
5 x 5 = 25 |
25 - 21 = 4 |
21 + 25 = 46 |
LCM of 50 and 70 = 350
Number of sets of 3 white balls in a length of 350 cm
= 350 ÷ 50
= 7
Number of white balls in a length of 350 cm
= 7 x 3
= 21
Number of sets of 5 brown balls in a length of 350 cm
= 350 ÷ 70
= 5
Number of brown balls in a length of 350 cm
= 5 x 5
= 25
Extra number of brown balls in a length of 350 cm
= 25 - 21
= 4
Number of sets of balls
= 12 ÷ 4
= 3
Total number of balls in one set of 350 cm of white balloons and one set of 350 cm of brown balloons
= 21 + 25
= 46
Total number of balls of the two ribbons
= 3 x 46
= 138
Answer(s): 138