Verbal Reasoning - Mental Ability Questions

In the following question, select the missing number from the given series.
1, 3, 6, 10, 15, ?

Shubham's mother is the sister-in-law of Shashi and Shashi is the only daughter of Parmeshwar. Ravi is Shubham's brother. How is Shashi related to Ravi?

In the following question, select the related number from the given alternatives.
4 : 17 : : 7 : ?

If '+' means '÷', '÷' means '­', '­' means 'X' and 'X' means '+', then 48 + 16 x 4 ­2 ÷ 8 = ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

LT, MS, NR, OQ, ?

In the following question, select the related word pair from the given alternatives.

Power : Watt : : ? : ?

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.
VWX, BCD, HIJ, ?

There are 45 trees in a row. The lemon tree is 20th from right end. What is the rank of lemon tree from left end?