Question

A student takes an exam. The ratio of her right answers to her wrong answers is 10 to 3. Which of the following could describe this situation?

She answered 20 wrong and 23 right.

She answered 70 wrong and 21 right.

She answered 21 wrong and 70 right.

She answers 23 wrong and 20 right.

Answer 1

The correct answer is: She answered 21 wrong and 70 right.

Answer 2

Find a number of right that is a multiple of 10.

There are such lines:

21 wrong and 70 right: this is 70/21 = 10/3 = 10:3

23 wrong and 20 right

The correct answer is the third choice.