If the ratio of red to blue marbles is 5:3 , and there are 15 red marbles, how many blue marbles are there?

9

Step-by-step explanation:

The 5 part of the ratio relates to 15 red marbles.

Dividing by 5 gives the value of one part of the ratio.

15 ÷ 5 = 3 ← value of 1 part of the ratio, thus

3 parts = 3 × 3 = 9 ← number of blue marbles

9 blue marbles

Step-by-step explanation:

I think the answer is 9 because if there are 15 red marbles and the ratio is 5:3, then 5*3=15; therefore, 3*3=9.

This is why the answer is 9 blue marbles.

Hope this helps!

9,000 euros.

Step-by-step explanation:

If the total is x euros the amount that Bella and Martha got  is

x - 1/2 x - 1/3 x and this = 2*750 = 1500 euros.

x - 3/ 6 x - 2/6 x = 1500

x - 5/6 x = 1500

1.6 x = 1500

x = 1500 * 6 = 9,000 euros.