Answer: Option [B]

According to the question,

Marks of (Economics + Political Science + Geography) = 120 + Political Science

So, the marks of other 2 subjects Economics and Geography is equal to 120

Economics + Geography = 120

120/2 = 60

Questions

1
The total marks obtained by a student in Economics, Political Science and Geography together is 120 more than the marks obtained by him in Political Science. What are the average marks obtained by him in Economics and Geography together?

Answer: Option [B]

According to the question,

Marks of (Economics + Political Science + Geography) = 120 + Political Science

So, the marks of other 2 subjects Economics and Geography is equal to 120

Economics + Geography = 120

120/2 = 60

2
The average marks of 90 students in a class was calculatd as 144. It was later realised that the marks of one of the students was 148 whereas, his actual marks was 156. What is the actual average marks of the group of 90 students? (Rounded off two digits after decimal)

Answer: Option [A]

The total marks of 90 students = 90 x 144 = 12960

According to the question, the marks of one of the students was 148 whereas, his actual marks was 156

So, the total marks = 12960 - 148 + 156

= 12968

So the average = 12968/90

= 144.09

3
The average of 5 positive integers is 528. The average of the first two numbers is 408 and the average of last two numbers is 554. What is the third number?

Answer: Option [C]

Let the third number be x,

According to the question,

(408 * 2 + x + 554 * 2)/5 = 528

408 * 2 + x + 554 * 2 = 2640

x = 954

4
The average monthly income of a family of 5 earning members was Rs.20200. One of the daughter in the family got married and left home. So the average monthly income of the family come down to Rs.18740. What is the monthly income of the married daughter?

Answer: Option [B]

The sum of monthly income of the family before the marriage of the daughter is:

5 x 20200 = Rs.101000

The sum of monthly income of the family after the marriage of the daughter is:

4 x 18740 = Rs.74960

The income of the aughter was Rs.101000 - Rs.74960 = Rs.26040

5
The total ages in a class of 80 girls is 1070 year. The average age of 25 of them is 13 year and that of another 25 is 16 year. Find the average age of the remaining girls?

Answer: Option [A]

The total age of first 25 girls is 25 x 13 = 325 year

The total age of second 25 girls is 25 x 16 = 400 year

The total age of first 50 girls = 725 year

The number of girls remained to calculate 30

So the total age of these 30 girls is (1070-725) year = 270 year

270/30 = 9 year