Yes I think (A) is the correct answer
The answer is:
D.90
I hope I helped
Didn't answer all because I got lazy and I think you should try and do the rest yourself. Did this in 5 mins, try putting more effort into your homework. This is basic mathematics.
Mount everest (Himalayas) and mount elbert (rocky mountains)
To find your answer you would divide 21 by 3 which would be 7, once you've got 7 you would multiply it by 9 which would give you the amount of old houses that there is which would be 63.
