There are some students in the bird park.
310 of them are boys, of whom 30% of them do not wear watches.
37 of the girls do not wear watches. What is the percentage of the students in the bird park who do not wear watches?
Boys |
Girls |
Total |
3x10 = 30 u |
7x10 = 70 u |
10x10 = 100 u |
No watches |
Watches |
No watches |
Watches |
|
3x3 |
7x3 |
3x10 |
4x10 |
|
9 u |
21 u |
30 u |
40 u |
100 u |
30% =
30100=
310 The number of boys is the repeated identity. Make the number of boys the same. LCM of 3 and 10 is 30.
Number of students who do not wear watches
= 9 u + 30 u
= 39 u
Total number of students
= 9 u + 21 u + 30 u + 40 u
= 100 u
Percentage of the students in the bird park who do not wear watches
=
39100 x 100%
= 39%
Answer(s): 39%