Question 35951
First you know that you can purchase 3 tacos for $1.17. You want to know how many tacos can be bought for $15.21.

For this type of problem you need to use a proportion.

Step 1.

3 tacos------> $1.17

"X" tacos-----> $15.21

Step 2.

You will use cross multiplication. 3 X 15.21 which equals 45.63

Then you multiply "X" by 1.17 which equals 1.17X

Step. 3

Now you have a simple equation 1.17X=45.63

you then simplify the equation by dividing both sides by 1.17.

X=39

The Check Step.

So you have the answer of 39 tacos can be purchased for $15.21

You first find out how much 1 taco costs first.

You find this by taking 1.17/3 and you get $0.39

So at $0.39 per taco you multiply this by 39 and you get a total of $15.21