mark the correct answer.

find 60% of 180
a) 90 b)180 c)130 d)60

I hope this is not a trick question, because there is no correct answer!

60% of 180
= 60/100*180
= 0.6*180
= 108

Here's how you can reason without doing any multiplication:

60% is a little more than half, so answers less than or equal to half are rejected [(a) and (d)].

It is definitely not 100%, which is why (b) is eliminated.

Since neither 60 or 180 has a factor of 13, (c) cannot be the right answer.

Conclusion:
the answer is (e): none of the above.