A math question,please.

问题描述:

A math question,please.
I have to result this question by my exam,could any one help me?
question:
A car park measures 15 metres by 18 metres.A car occupies 6 square metres but two-fifths of the park must be left free for turing.What is the maximum cpacity of the car park?
A.18 B.3 C.36 D.9 E 27
I see the answer for E.i don't understand a lot.
thanks for everybody who could get us a reasonable answer.
Thank you!
如果复杂就用CHINESE吧,我的英文understanding比较limited

For each car,the real space is not 6,but 6 /(3/5) = 10
Then total number of cars in this parking lot:
15*18/10 = 3x9 = 27