The ratio of red marbles to blue marbles in a bag is 3 to 4 which of the following is possible total number of marbles

A. 21

B. 30

C. 32

D. 40

A. 21

Step-by-step explanation:

3+4 = 7

therefore the answer has to be a multiple of 7.

the only multiple of 7 on the list is A. 21

Therefore the answer is A

Option A.

Step-by-step explanation:

Given : ratio of red marbles to blue marbles in a bag is equal to 3 to 4.

We need to find which of the options: A, B, C and D is true.

Here, 3 + 4 = 7

Therefore, sum of number of red marbles and number of blue marbles should be multiple of 7, hence the answer has to be a multiple of 7.

Now, option B is 30 which is not multiple of 7.

Option C is 32 which is not multiple of 7.

Option D is 40 which is not multiple of 7.

Option A is 21 which is a multiple of 7.

Therefore, the only multiple of 7 on the list is A. 21

So, total number of marbles can be 21.

Therefore the answer is A