SOLUTION: Barry has a bag of marbles. 3/8 of the marbles are red. 70% of the remaining marbles are yellow. The other 12 marbles are green. How many marbles are there in the bag altogether?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Barry has a bag of marbles. 3/8 of the marbles are red. 70% of the remaining marbles are yellow. The other 12 marbles are green. How many marbles are there in the bag altogether?      Log On


   

Question 1203168: Barry has a bag of marbles. 3/8 of the marbles are red. 70% of the remaining marbles are yellow. The other 12 marbles are green. How many marbles are there in the bag altogether?
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52798) About Me  (Show Source):
You can put this solution on YOUR website!
.
Barry has a bag of marbles. 3/8 of the marbles are red.
70% of the remaining marbles are yellow. The other 12 marbles are green.
How many marbles are there in the bag altogether?
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Let x be the total marbles (altogether).


Write equation for total marbles

    %283%2F8%29x + 0.7%2A%285%2F8%29x + 12 = x.


To solve, multiply all the terms by 8; then simplify

    3x + 0.7*5x + 96 = 8x

    3x + 3.5x + 96 = 8x

    96 = 8x - 3x - 3.5x

    96 = 1.5x

     x = 96/1.5 = 64.


ANSWER.  There are 64 marbles in the bag.

Solved.



Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Given that 3/8 of the marbles are red, let 8x be the total number of marbles and 3x be the number of red marbles. Then the number of marbles of other colors is 8x-3x = 5x.

70% of the remaining marbles are yellow. 70% of 5x is 0.7(5x) = 3.5x.

The total number of red and yellow marbles is 3x+3.5x = 6.5x; the total number of marbles is 8x. So the number of green marbles is 8x-6.5x = 1.5x.

The number of green marbles is 12:

1.5x = 12
x = 12/1.5 = 8

ANSWER: The total number of marbles in the bag is 8x = 64