PSLEGillian had two strings of the same length. She cut the first string into equal parts of length 70 cm and to each part she tied 3 yellow stars. After that, she cut the second string into equal parts of length 100 cm and to each part she tied 5 pink stars. When she finished tying, she counted that there were 15 more pink stars than yellow stars. How many stars were there altogether?
|
First string |
Second string |
Difference |
Total |
Length of each part |
70 cm |
100 cm |
|
|
Number of balloons tied to each part |
3 yellow balloons |
5 pink balloons |
|
|
LCM |
700 cm |
700 cm |
|
|
Number of equal parts |
700 ÷ 70 = 10 |
700 ÷ 100 = 7 |
|
|
Number of balloons for each string per set |
10 x 3 = 30 |
5 x 7 = 35 |
35 - 30 = 5 |
30 + 35 = 65 |
LCM of 70 and 100 = 700
Number of sets of 3 yellow stars in a length of 700 cm
= 700 ÷ 70
= 10
Number of yellow stars in a length of 700 cm
= 10 x 3
= 30
Number of sets of 5 pink stars in a length of 700 cm
= 700 ÷ 100
= 7
Number of pink stars in a length of 700 cm
= 7 x 5
= 35
Extra number of pink stars in a length of 700 cm
= 35 - 30
= 5
Number of sets of stars
= 15 ÷ 5
= 3
Total number of stars in one set of 700 cm of yellow balloons and one set of 700 cm of pink balloons
= 30 + 35
= 65
Total number of stars of the two strings
= 3 x 65
= 195
Answer(s): 195