Find the missing number?

Sam ranked is 9th from the top and thirty-eighth from the bottom in a class. How many students are there in the class?

Study the following figure and answer the following questions.

1. Here the big triangle shows the artists.

2.Short represents triangular scientists.

3. The square refers to dancers.

4.The Circle refers to the doctors.

Which letter represents artists who are neither doctors, nor scientists nor dancers?

Looking at one person, a woman said, "His brother's father is the only son of my grandfather." How is the woman related to that person?

An assertion (A) and a reason (R) are given below –
Assertion (A) :- Agricultural activities are less on mountainous region.
Reason (R) :- Mountains have less fertile terrain and difficult weather conditions.
Choose the correct option :-

Arrange the words given below in a meaningful sequence.
 1. Presentation
 2. Recommendation
 3. Arrival
 4. Discussion
 5. Introduction

85 : 42 : : 139 : ?