Final answer:
To solve each proportion, use the cross-product method by multiplying the numerator of the first ratio by the denominator of the second ratio and vice versa. Then simplify and solve for the unknown variable.
Step-by-step explanation:
To solve each proportion, we can use the cross-product method. Here's how:
a. x/24 = 30/36
Cross multiplying, we get x * 36 = 24 * 30.
Simplifying, we have 36x = 720.
Dividing both sides by 36, we find that x = 20.
b. 5/7 = x/3
Cross multiplying, we get 5 * 3 = 7x.
Simplifying, we have 15 = 7x.
Dividing both sides by 7, we find that x = 15/7 or approximately 2.14.
c. If Joan read 75 pages in 4 hours, how long will it take her to read 250 pages?
Let's set up a proportion. If Joan reads 75 pages in 4 hours, then 250 pages will take x hours.
Using the cross-product method, we have 75 * x = 4 * 250.
Simplifying, we get 75x = 1000.
Dividing both sides by 75, we find that x = 1000/75 or approximately 13.33 hours.