Question

The arithmetic mean of 2 numbers is 10 and geometric mean is 8.calculate the 2 numbera

Answer 1

Although you can pretty well figure it out by inspection/trial and error, here it is analytically 

(a + b)/2 = 10; a = 20 - b 
√ab = 8; ab = 64..........substitute for a 

20b - b^2 = 64 
b^2 - 20b + 64 = 0 
(b - 4)(b - 16) = 0 

The two numbers are 4 and 16