25% of the people are performers for a concert and the rest are spectators. 70% of the spectators are parents and there are 1200 more parent spectators than child spectators. How many parent spectators must leave so that 5% of the people are parent spectators?
|
Performers |
Spectators |
|
1x10 |
3x10 |
|
|
Children |
Parents |
|
|
3x3 |
7x3 |
Before |
10 u |
9 u |
21 u |
Change |
|
|
- ? |
After |
19x1 = 19 u |
1x1 = 1 u |
25% =
25100 =
14 70% =
70100 =
710 5% =
5100 =
120The total number of spectators at first is repeated. Make the total number of spectators the same. LCM of 3 and 10 is 30.
Number of more parent spectators than child spectators at first
= 21 u - 9 u
= 12 u
12 u = 1200
1 u = 1200 ÷ 12 = 100
If some parent spectators leave, the total number of child spectators and performers remains unchanged.
Number of parent spectators who must leave so that 5% of the people are parent spectators
= 21 u - 1 u
= 20 u
= 20 x 100
= 2000
Answer(s): 2000