Statistics - Question on Frequency

I have this question on Frequency, but I've forgotten how to do it. Here's the question:

The lengths of girls' hair, in a particuler school, is recorded in the table below:

Length (cm)........... 0-5.......6-10.......11-15.......16-25.......26-50

Frequency ............. 22........ 27 ..........31........... 54.......... 35

Frequency Density

a) Which is the modal class?

b) How many of the girls are outside the modal class?

c) Draw a histogram showing this data.

d) Estimate the number of girls whose hair is less than 8cm in length.

So, please help, I haven't got long eft to do it. Links or you posting help would be great. Thanks :)