6.

The average monthly income of P and Q is Dollar 5050. The average monthly income of Q and R is Dollar 6250 and the average monthly income of P and R is Dollar 5200. The monthly income of P is:


A. Dollar 3500 B. Dollar 4000
C. Dollar 4050 D. Dollar 5000
Answer and Explanation
Answer: Option B
Explanation: Let P, Q and R represent their respective monthly incomes. Then, we have:

P + Q = (5050 x 2) = 10100 .... (i)

Q + R = (6250 x 2) = 12500 .... (ii)

P + R = (5200 x 2) = 10400 .... (iii)

Adding (i), (ii) and (iii), we get: 2(P + Q + R) = 33000 or P + Q + R = 16500 .... (iv)

Subtracting (ii) from (iv), we get P = 4000. P's monthly income = Dollar 4000.

7.

The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is:

A. 35 years B. 40 years
C. 50 years D. None of these
Answer and Explanation
Answer: Option B
Explanation: Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.

Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.

Husband's present age = (90 - 50) years = 40 years.

8.

A car owner buys petrol at Euro 7.50, Euro 8 and Euro 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Euro 4000 each year?

A. Euro 7.98 B. Euro 8
C. Euro 8.50 D. Euro 9
Answer and Explanation
Answer: Option A
Explanation:

Averages Questions and Answers

 

 

 

 

 

 

Total amount spent = Euro (3 x 4000) = Euro 12000. Average cost = Euro (12000 x 51)/76700 = Euro 6120/767 = Euro 7.98

9.

In Jessica's opinion, her weight is greater than 65 kg but less than 72 kg. Her brother doest not agree with Jessica and he thinks that Jessica's weight is greater than 60 kg but less than 70 kg. Her mother's view is that her weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Jessica?

A. 67 kg. B. 68 kg.
C. 69 kg. D. Data inadequate
Answer and Explanation
Answer: Option A
Explanation: Let Jessica's weight by X kg.

According to Jessica, 65 < X < 72

According to Jessica's brother, 60 < X < 70.

According to Jessica's mohter, X <= 68

The values satisfying all the above conditions are 66, 67 and 68.
10.

The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is:

A. 17 kg B. 20 kg
C. 26 kg D. 31 kg
Answer and Explanation
Answer: Option D
Explanation: Let A, B, C represent their respective weights.

Then, we have: A + B + C = (45 x 3) = 135 .... (i)

A + B = (40 x 2) = 80 .... (ii)

B + C = (43 x 2) = 86 ....(iii)

Adding (ii) and (iii), we get: A + 2B + C = 166 .... (iv)

Subtracting (i) from (iv), we get : B = 31.

B's weight = 31 kg.