12 balloons in 2 boxes, 78 balloons in x boxes. I know the answer is x=15, but I don't know how to write a proportion for it.

Question

tylerd · Answer

.12=2b

78=ab

tylerd · Answer

solve for b first

then solve for a

tylerd · Answer

actually let me check real quick

anonymous · Answer

$$\frac{ 12 }{ 2 } = \frac{ 78 }{x}$$

I usually see it like this, but tyler's way probably works too (it is a bit more complicated)

anonymous · Answer

you can type flip the fractions too! as long as everything lines up horizontally, then the ratio must hold.

tylerd · Answer

pretty sure ya

anonymous · Answer

Thank y'all so much! I see what I did wrong now, I didn't put the "1" in "12" on my calculator and kept getting 39. Thanks!

triciaal · Answer

why is the answer 15?

12:2 = 78:x     x = 78/12*2 
x = 13

anonymous · Answer

You are correct the answer is 13. Where did you get 15?