There is a bag of marbles that has 40% blue marbles, 10% red marbles, 30% green marbles, and 20% black marbles. What is the ratio of red marbles to black marbles?

1/2 :D?

Step-by-step explanation:

You just need to divide the percentage of red marbles to black marbles.

10% / 20% = 1/2 :D

answer: a

step-by-step explanation:

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.