You have 5 faceup cards and 12 facedown cards. You add some faceup cards so 2 out of every 5 cards are faceup. How many cards are there now?

How would a proportion look for this problem?

Question

You have 5 faceup cards and 12 facedown cards. You add some faceup cards so 2 out of every 5 cards are faceup. How many cards are there now?

How would a proportion look for this problem?

anonymous · Answer

assuming x is additional face-up:
$$(5+x)/(12) = 2/5$$

anonymous · Answer

Draw a proportion for me. I understand that way of doing it. But my teacher is looking for a proportion.

anonymous · Answer

Like a ratio? solve for x, then the answer is 5+x:12

anonymous · Answer

Example |dw:1336425208681:dw|