Verbal Reasoning - Mental Ability Questions

In the following question, correct the equation by interchanging two signs.
4 – 10 x 5 + 9 ÷ 3 = 51

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?
J_J_L_KL_JK_MN

Consider the following information and answer questions based on it.

Seven bottles colored - brown, blue, black, violet, white, indigo and purple are kept in a row, in random order, from left to right such that the -

1. White and purple bottles are not at either extremes.

2. Brown bottle is to the immediate right of violet bottle and to the immediate left of the white bottle.

3. White, violet and brown bottles are not at the center.

4. Black bottle is to the immediate left of purple bottle.

5. Blue bottle is neither second last nor at either extremes.

Which bottle is at the center of the row?

How many such pairs of letters are there in the word REGIONAL, each of which has as many letters between them in the word (in both forward and backward directions) as they have between them in the English alphabetical series ?

In the following question, select the related number from the given alternatives.
40 : 100 : : 56 : ?

In a row of students, if John , who is 16th from the left, and Johnson, who is 8th from the right, interchange their positions, John becomes 33rd from left. How many students are there in a row?

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

8,24,12,?,18,54

Ram went 20 meters to the north then turned towards east and walked another 5 meters, then he turned towards right and covered 20 meters. How faris he from the starting point?