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

12664   34    20  14 ?

Each internal angle of regular polygon is two times its external angle. Then the number of sides of the polygon is: 

The average of five consecutive number is 26, then the multiple of the first and the last number is

If a cuboid of dimensions 64cm×16cm×8cm is melted and recast into two equal cubes of same size. Then what will be the ratio of the surface are of cuboid to the total surface area of the two cubes?

Vessels A and B contain mixture of milk and water in the ratios 4 : 5 and 5 : 1 respectively. In what ratio should quantities of mixture be taken from A and B to from a mixture in which milk to water is in the ratio 5 : 4 ? 

If the angle of elevation of the Sun changes from 30 ° to 45 °, the length of the shadow of a pillar decreases by 20 meters. The height of the pillar is 

129 meter from the foot of a cliff on level of ground, the angle of elevation of the top of cliff is 30 °. The height of this cliff is 

If the cost of 1 dozen apples is Rs. 18, then the cost of 25 apples will be -