10% of the people are performers for a concert and the rest are spectators. 80% of the spectators are parents and there are 1080 more parent spectators than child spectators. How many parent spectators must leave so that 65% of the people are parent spectators?
|
Performers |
Spectators |
|
1x5 |
9x5 |
|
|
Children |
Parents |
|
|
1x9 |
4x9 |
Before |
5 u |
9 u |
36 u |
Change |
|
|
- ? |
After |
7x2 = 14 u |
13x2 = 26 u |
10% =
10100 =
110 80% =
80100 =
45 65% =
65100 =
1320The total number of spectators at first is repeated. Make the total number of spectators the same. LCM of 9 and 5 is 45.
Number of more parent spectators than child spectators at first
= 36 u - 9 u
= 27 u
27 u = 1080
1 u = 1080 ÷ 27 = 40
If some parent spectators leave, the total number of child spectators and performers remains unchanged.
Number of parent spectators who must leave so that 65% of the people are parent spectators
= 36 u - 26 u
= 10 u
= 10 x 40
= 400
Answer(s): 400