Question

The two geometric means between the numbers 1 and 64 are 

A. 1 and 64 

B. 4 and 16 

C. 2 and 16 

D. 8 and 16

Answer 1

Let the GM be y,z 

∴ 1,y,z,64 

y² = 1.z ; z² =64y 

y⁴ = z² 

∴ y⁴ =64y 

⇒ y = 4 

∴ Z =16

∴ The two GM are 4,16.