Answer:
She should sell 20 band posters from total 80 to keep the maintain the same ratio.
Step-by-step explanation:
The total number of movie posters collector has = 120
The total number of band posters collector has = 80
The current ratio of movie poster : band poster = 120 : 100
or, reducing the ratio further, we get
ratio of movie poster : band poster = 6 : 5 ...... (1)
Now, the number of posters she wants to sell = 24
So, the remaining movie poster left = 120 - 24 = 96
Let us assume she sells m band posters to keep the ratio equal.
So, the number of band posters she is left with = 100 - m
⇒The ratio of movie poster left : band poster left = 96 : 100 - m .. (2)
Now here as the ratio remains same after selling m band posters, so
or, m = 20
Hence, she should sell 20 band posters from total 80 to keep the maintain the same ratio.