Respuesta :

Answer:

15

Step-by-step explanation:

Red : Blue :

3        8

We have 40 blue marbles

Multiply 8 by what to get 40

40/8 =5

So we need to multiply by 5

Red : Blue :

3*5      8*5

15         40

There are 15 red marbles

Answer:

15 red marbles

Step-by-step explanation:

15 red marbles because 40 divided by 8 is 5. since the ratio from red to blue marbles is 3 to 8 this makes us have to multiply 5 x 3 because of how many times 8 goes into 40.