Let's set up a proportion. The numbers are in a ratio of 2 to 3, and the smaller number is 18, while the larger number is unknown. We can call it x.
smaller/larger=smaller/larger
2/3=18/x
Cross multiply. Multiply the numerator of the first fraction by the denominator of the second. Then, multiply the numerator of the second by the denominator of the first.
2*x=3*18
2x=54
We want to find out what x is. We have to get x isolated. Currently, x is being multiplied by 2. The inverse of multiplication is division. Divide both sides by 2.
