Paul and Harry each had a collection of fossils. Harry had 2/5 as many fossils as Paul. When Paul lost 20 fossils, Harry then had twice as many as Paul. How many fossils were in Paul's collection at first?
h = 2/5 p This is given
h = (p-20) * 2 sub in the red equation
2/5 p = 2p -40
-8/5 p = -40
p = 40 * 5/8 = 25 origianlly had paul