Answer:
6.
Step-by-step explanation:
x/7 - 3/8 = 27/56
Multiply through by 56 , as 7 * 8 = 56 we have:
8x - 3*7 = 27
8x = 27 + 21 = 48
x = 6.
If we call the number "x" then:
x*25%=21
x*25/100=21
x=21*4
x=84
Hope this helps. :)
I am pretty sure the height is 4, but sorry if i am wrong