Mark the correct alternative in each of the following:
Let x be the A.M. and y, z be two G.M.s between two positive numbers. Then, is equal to
Let the numbers be a,b.
a,x,b = 2x =a+b
a,y,z,b = y2 = az ; z2 =by [a,b,c GM =b2 =ac]
⇒