The 3rd and 8th term of an arithmetic  progression are 19 and 49 respectively. What is the 13th term?

Suresh is half his father’s age. After 20 years, his father’s age will be one and a half times Suresh’s age. What is his father’s age now?

10 year ago, the ages of A and B were in the ratio 13 :17 respectively. 17 year from now the respective ratio of their ages will be 10:11. what is the age of B at present?  

Directions : What should come in place of the question mark (?) in the following number series? 

474 459 429 369 249 ?

Directions : What should come in place of the question mark (?) in the following number series? 

87 89 95 107 ? 157 

Directions : What should come in place of the question mark (?) in the following number series? 

19 38 ? 228 684 1368 

Directions : What should come in place of the question mark (?) in the following number series? 

55 109 ? 433 865 1729 

Directions : What should come in place of the question mark (?) in the following number series? 

7 17 54 ? 1098 6591