Question

In a probability experiment, Craig rolled a six-sided die 55 times. The die landed on a number greater than three 31 times. What is the ratio of rolls greater than three to rolls less than or equal to three?
A. 31/24

B. 55/31

C. 24/31

D. 31/55

Answer 1

31/55 times he rolled a number greater than 3.
Either you roll a number > 3, or you roll a number ≤3.
55/55 - 31/55 = 24/55 times he rolled a number less than or equal to 3.

Now we want the ratio of 31/55 to 24/55.
Mutliply each side by 55 and we get 31/24.

Answer 2

The answer is A because:
rolls greater than three/rolls less than or equal to three
rolls greater than three: 31
rolls less than or equal to three: 55-31 = 24
rolls greater than three/rolls less than or equal to three = 31/24