Harmonic Mean of 2 numbers

If harmonic mean of numbers (1)/(2),(1)/(2^(2)),(1)/(2^(3)),............(1)/(2^(10)) is (lambda)/(2^(10)-1) then lambda is equal to

If the ratio of the arithmatic mean and the geometric mean of two positive numbers is 3:2 , then find the ratio of the geometric mean and the harmonic mean of the numbers.

The arithmetic mean and geometric mean of two numbers are 14 and 12 respectively. What is the harmonic mean of the numbers

The harmonic mean of two numbers is 4. Their arithmetic mean A and the geometric mean G satisfy the relation 2A+G^(2)=27. Find two numbers.

The harmonic mean of two numbers is 21.6. If one of the numbers is 27, then what is the other number?

If the arithmetic and harmonic means of two numbers are 4.5 and 4 respectively,then one of the number is