Question 1207651
<pre>
Let T = the total price of the gift and M = How much more money Jolene paid 
than Iris.

{{{system(I+J+K=T,I+J = (3/5)T ,  I+K=(13/20)T , J+K=195 , M = J-I  )}}}

Put those equations in an online solver and instantly get

J = 91, K = 104, I = 65, M = 26, T = 260

The answer is M = 26

[These days, there are online solvers for almost anything in mathematics.] 

Edwin</pre>