SOLUTION: The ratio of blue marbles to red marbles in a jar is 13 to 5. If there were a total of 2610 marbles in the jar, how mwny were red?

Question 212188: The ratio of blue marbles to red marbles in a jar is 13 to 5. If there were a total of 2610 marbles in the jar, how mwny were red?
Found 2 solutions by rfer, checkley77:
Answer by rfer(16322) (Show Source): You can put this solution on YOUR website!
13x+5x=2610
18x=2610
x=145
red=145*5=725
blue=145*13=1885
total=2610
Answer by checkley77(12844) (Show Source): You can put this solution on YOUR website!
13/5=x/(2610-x)
13(2610-x)=5x
33,930-13x-5x=0
-18x=-33,930
x=-33,930/-18
x=1,885 number of blue marbles.
2,610-1,885=725 red marbles.
13/5=1885/725
5*1885=13*725
9,425=9,425

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