what percent of 12 is 18

Let's break this down

We can write "what percent" as.....   x/100

"Of 12" means to multiply by 12

"Is 18" means "equal to 18" or   "= 18"

So we have

(x/100) ( * 12)  (= 18)     ......so.......  

x/100 * 12  =  18        divide both sides by 12

x/100  =  18/12           express 18/12 as a decimal = 1.5

x/100 = 1.5                 multiply both sides by 100

x =   150

So... x/100.....  =   150/100  = 150%

So 18 is 150%  of 12