Question 807034
the difference between a number divided by 3 and 4 is 20.
{{{n/3}}} - {{{n/4}}} = 20
multiply by 12
4n - 3n = 12(20)
n = 240 is the number
and, 
Aubrey has $120 to spend on a tennis racket and lessons.
 The racket costs $45 and the lessons cost $15/hr. 
How many hours of lessons can she afford?
hrs = {{{(120-45)/15}}}
hrs = 5 hrs