If 1 , a, b and 4 are in harmonic progression , then the value of a + b is equal to

If 2, h_(1), h_(2),………,h_(20)6 are in harmonic progression and 2, a_(1),a_(2),……..,a_(20), 6 are in arithmetic progression, then the value of a_(3)h_(18) is equal to

If 2, h_(1), h_(2),………,h_(20)6 are in harmonic progression and 2, a_(1),a_(2),……..,a_(20), 6 are in arithmetic progression, then the value of a_(3)h_(18) is equal to

Three numbers a, b and c are in geometric progression. If 4a, 5b and 4c are in arithmetic progression and a+b+c=70 , then the value of |c-a| is equal to

Three numbers a, b and c are in geometric progression. If 4a, 5b and 4c are in arithmetic progression and a+b+c=70 , then the value of |c-a| is equal to

If in the triangle ABC, "tan"(A)/(2), "tan"(B)/(2) and "tan"(C )/(2) are in harmonic progression then the least value of "cot"^(2)(B)/(2) is equal to :

If the numbers a, b, c, d, e are in arithmetic progression then find the value of a - 4b + 6c - 4d + e.

IF a,b and c are in arithmetic progression, then (b-a)/(c-b) is equal to:

If three real numbers a,b and c are in harmonic progression, then which of the folllowing is true ?

Let the harmonic mean of two positive real numbers a and b be 4. If q is a positive real number such that a,5,q,b is an arithmetic progression , then the value (s) of abs(q - a) is (are)