If the arithmetic mean of p and q is 10 and the arithmetic mean of q and r is 27, what is the value of r-p?
Pick one:
A) 20 B) 10 C) 34 D) 40 E) 5
Arithmetic mean expression for p and q:   (p+q)/2=10 ; p+q=20 ----eq1   Arithmetic mean expression for q and r:   (q+r)/2=20 ; q+r=54 ----eq2   Subtracting eq1 from eq2 we get: r-p=34   Hence, the correct answer is 34
<result>C</result>
If the arithmetic mean of p and q is 10 and the arithmetic mean of q and r is 27, what is the value of r-p?