ok this proportion is driving me nuts... question is the ratio of red to blue marbles is 5 to 7. if there are 156 marble in total, how many red marbles are there?

Question

myininaya · Answer

$$\frac{r}{b}=\frac{5}{7}$$

$$r+b=156$$

myininaya · Answer

do you see how I got those equations?

myininaya · Answer

by the way r is red marbles and b is blue marbles

anonymous · Answer

See out of total 12 (5+7) marbles 5 are red i.e 5/12

so

5
--- * 156 = no of red marbles 
12 

so no of red marbles is 65

anonymous · Answer

i do looki at them but was setting up to do cross multiply 5/7=156/x

anonymous · Answer

5/6 is ratio of red and blue marbles and 156 is total number of marbles so u can't form this relation...

myininaya · Answer

$$r=\frac{5b}{7}$$

$$\frac{5b}{7}+b=156$$


$$\frac{5b+7b}{7}=156$$

$$\frac{12b}{7}=156$$

$$b=156*\frac{7}{12}=91$$

but that means we have r+91=156
which means r=156-91=65