Question 701119
because 15 questions is 60%
to find what 1 question is worth divide by 15.
this gives 1 question is worth 4%. 
Now we need to find out how many questions make 100%.
{{{(100/4)=25}}}
so there are 25 questions in the test
OR
You could say....
because 60% is 15 questions 
then to find what 10% is we divide by 6
10%={{{15/6}}}=2.5 questions
to find 100% multiply by 10
100%=25 questions
there are 25 questions in the test