If a , b , c are in AP and x , y and z are in GP , then $${x^{b-c}.{y^{c-a}.z^{a-b}=?}}$$

Direction (66-70): What should come in place of the question mark(?) in the following number series?

12664   34    20  14 ?

The average of five terms is 40. If the first four terms are given as 50, 52, 35 and 46, find the fifth term.

If a, b and c are in GP and a^1/x=b^1/y=c^1/z. The value of 2y is?

What will come in place of the question mark (?) in each of the following series?

15     ?    24    33     97    122     

Find the next term in the series.

1329, 997, 725, 507, 337, ?

What should come in place of the question mark '?' in the following number series?

17, 52, 158, 477, ? , 4310

117.5, 117, 119, 111, 143, ?