Final answer:
To find the number of mountain bikes in the store, we can set up a proportion using the ratio given. The store has 90 BMX bikes and the ratio is 3 to 2. Therefore, the store has 60 mountain bikes.
Step-by-step explanation:
To find the number of mountain bikes in the store, we can set up a proportion using the ratio given. The ratio of BMX bikes to mountain bikes is 3 to 2. This means for every 3 BMX bikes, there are 2 mountain bikes.
Therefore, we have the proportion:
3 BMX bikes / 2 mountain bikes = 90 BMX bikes / x mountain bikes
By cross-multiplying, we get:
3x = 2 * 90
Dividing both sides by 3, we find:
x = (2 * 90) / 3
x = 60
So, the store has 60 mountain bikes.