hello i am in urgent need of help with 2 questions the first one is an inequality

Find all the integer values of n which satisfy

-15 < 5n <= 20

and the second one may sound stupid but i couldnt get it

anna drove 35 miles from southhampton to basingstoke

she drove at an average speed of 20 mph for the first 5 miles

and then an average speed of 60 mps for the remaining 30 miles

calculate her average speed for the whole journey.

plz help and if you say how you got would be better thanks!