Verbal Reasoning - Mental Ability Questions

From the word 'ASTOUNDER', how many independent words can be made with-out changing the order of the letters and using each letter only once ? 

Arrange the given words in the sequence in which they occur in the dictionary.

i. Argument
ii. Augmentation
iii. Agility
iv. Astute

In the following question, select the missing number from the given series.

11, 13, 16, 18, 21, ?

Arrange the given words in the sequence in which they occur in the dictionary.

1. Dispel

2. Dispute

3. Distinct

4. Dissent

5. Disrupt

In the following question, select the missing number from the given series.

57, 69, 81, 93, ?, 117

In the following question, select the missing number from the given series.

17, 20, 23, 26, 29, ?

In the following question, select the missing number from the given series.

2, 5, 9, 14, 20, ?

Consider the following information and answer the questions based on it.

Out of the 75 birders, 15 wanted to see only sunbird, 10 wanted to see only flycatcher, 12 wanted to see both sunbird and nuthatch, 15 wanted to see only bee-eater, 13 wanted to see both sunbird and bee-eater, 5 wanted to see both flycatcher and nuthatch and the remaining wanted to see only nuthatch.

How many birders wanted to see only one bird?