Math.percent

Problem	Method of Math.percent
$p\%$ from $a$	pa(p,a) or ap(a,p)
number whose $p\%$ equals $b$	pb(p,b) or bp(b,p)
percentage of $b$ in $a$	ab(a,b) or ba(b,a)

To remember names of these methods, you can associate p with percent, a with greater number (or entire/context number) and b with less number (number being a part of the entire number - a)

Example

Math.percent.pa(25,200)
// 50 (25% from 200 is 50)

Math.percent.pb(25,50)
// 200 (200 is number whose 25% is 50)

Math.percent.ab(200,50)
// 25 (25% is percentage of b in a)