Question 4127
"50%" means .50

"what #" means x

"is" means =


Use this to write the equation"


50% of what # is 30
.50 times x   =  30


.50x = 30

Divide both sides by .50, which gives you 

{{{.50x/.50 = 30/.50}}}

Either use a calculator or multiply numerator and denominator by 10

x = 60.

There are other methods that might be easier.  I can't remember them.  Maybe someone else can.