Suppose A.M. of two positive numbers be 7 and G.M. between them be 5. The A.M. between their squares  is

Let two positive numbers be a, b. Then  a+b=2(7)=14 and  ab=5 or ab=25Now, a2+b2=(a+b)2−2ab=196−50=146⇒12a2+b2=73