If Ahmed answered 60% of the questions of a test with true answers and the number of questions which were answered incorrectly are 10 questions, then the number of all questions of the test is ...

Question

shadowlegendx · Answer

In the depths of my mind I know how to solve this but its late where I am :/ 
I don't know if this helps but:

60%= .60
10= 40%
40%= .40

I know in order to solve it you had to change something into decimal form and muliple it from there or something....idk...srry I wasnt of much help