Question

There are 3 red marbles for every 7 blue marbles in a box.

If the box has 40 marbles, how many marbles are blue?



______ marbles are blue.

Answer 1

That means that for every ten marbles, 7 are blue.

40 = 4 * 10

4 * 7 = ?

Answer 2

3 red marbles + 7 blue marbles = 10 marbles

The box has 40 marbles , that is 4 times more than 10.

4 ∙ 7 = 28 blue marbles

4 ∙ 3 = 12 red marbles

Checking the results:

7 blue marbles / 3 red marbles = 28 blue marbles /12 red marbles

7 / 3 = 28 / 12

7 / 3 = 4 ∙ 7 / 4 ∙ 3 = 7 / 3

Answer 3

[AI-generated answer — Explain Bot]

To find the number of blue marbles, we need to determine the ratio of red to blue marbles in the box.

Given that there are 3 red marbles for every 7 blue marbles, we can represent this as a fraction: 3/7.

To determine the number of blue marbles, we need to find the fraction of blue marbles out of the total number of marbles in the box. Since there are 40 marbles in total, we can set up the following proportion:

(7 blue marbles) / (40 total marbles) = (3/7)

To solve this proportion, we can cross-multiply and then solve for the unknown value:

7 * (3/7) = 3 * (40)
21/7 = 120

Simplifying the fraction, we get:

3 = 120/7

Therefore, there are 17 blue marbles in the box.

17 marbles are blue.