Posted by **shank** on Sunday, May 1, 2011 at 7:53pm.

a bag of marbles contains 5 red,7 green ,and some blue.if 1/3 of the marbles in the bag are blue,how many blue marbles are in the bag?

- math -
**MathMate**, Sunday, May 1, 2011 at 8:21pm
If there are only red, green and blue marbles in the bag, then given that 1/3 are blue, then red and green occupy 1-1/3=2/3 of the bag.

Use direct proportion:

2/3 bag : 5+7=12

1/3 bag : X

Cross multiply:

x=(1/3)*12÷(2/3)

=12/2

= 6 (blue marbles)

## Answer this Question

## Related Questions

- math - There are 25 red, blue, yellow and green marbles in a bag. Four of the ...
- Math - A bag contains nine red marbles, four green marbles, three blue marbles, ...
- math - There are 5 red marbles, 6 blue marbles, e green marbles, and 2 yellow ...
- math - a bag contains 33 green marbles and 25 blue marbles. you select a marble ...
- math - A bag contains 5 red, 4 white and 6 blue marbles. Another bag with 9 blue...
- Maths - Matt has a bag containing 12 green marbles and 8 blue marbles. Without ...
- math - sally has a bag with red,blue, and green marbles. She has twice as many ...
- math - George has a bag of marbles. Inside the bag are 5 red marbles, 3 green ...
- math - George has a bag of marbles. Inside the bag are 5 red marbles, 3 green ...
- Math - One bag contains 5 red marbles, 4 blue marbles, and 3 yellow marbles, and...

More Related Questions