Question

You have 16 coins that are heads up and 18 coins that are tails up. After you add some coins that are tails up, the ratio of heads up to tails up is 1 to 1.5
How many coins are tails up?


How many coins in all?

Answer 1

So 16=heads
18=tails
after you add some tails
18+x

ratio of heads to tails is 1:1.5
heads=16, didn't change
tails=18+x

so
1:1.5=16:18+x
fractionify
1/1.5=16/(18+x)
1/1.5=2/3
2/3=16/(18+x)
mutiply both sides by (3)(18+x)
2(18+x)=3(16)
36+2x=48
subtract 36 from both sides
2x=12
divide 2
x=6

6 tails added


total=heads+tails
heads=16
tails=18+6=24
total=16+24
total=40



6 tails added
40 total coins