Because the triangles are similar
ac/pr=bc/qr
8/pr=10/4
10*pr=8*4
10pr=32
pr=32/10
pr=3,2
5/2=40/16. You can try to cross multiply by 2 times 40 and dividing by 16 to get 5.
Answer:
6m+7.5
Step-by-step explanation:
the arithmetic mean is the average of two numbers
it is given that a is average of 6m and 10
so 
b is the average of 4m and 4
so 
c is the average of 14m and 16
so 
now the average of a ,b and c is given by

24 hurry is that one in my but