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Aptitude - Averages Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to Averages. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Q 1 - Find out the average of A and B if the given value of 16A+ 16B = 48

Answer : A

Explanation

16a+16b = 48 ⇒ 16(a+b) = 48 ⇒ (a+b) = 3
So, we  have a and b average  is  (a+b)/2 = 3/2 = 1.5

Q 2 - 37 °C is mean temperature of 3 days Monday, Tuesday, Wednesday while 34°C is average of Tuesday, Wednesday and Thursday . What should be the temperature on Thursday if the temperature was 4/5 of that of Monday?

Answer : B

Explanation

M+ T+W =(37*3) = 111...(i)
T+W+Th= (34*3) = 102 ...(ii)
Th =4/5m ⇒ M = 5/4*th ...(iii)
(ii)-(i)  gives , M-Th = 9 ⇒ 5 Th /4 � Th =9
If we assume that x° is the temperature on Thursday. Then,
5x/4 �x =9 ⇒ 5x-4x = 36 ⇒ x = 36°
Hence, its proves that the Thursday temperature was 36°.

Q 3 - A committee have 8 person. If 35 year and 45 year aged lady replaced by two men in that case the average of age become more 2 year in the comparison of old one. Find out the average age of two men?

Answer : D

Explanation

Age increase  = (2*8) = 16 years.
Total age of two lady  who replaced = (35+45)= 80
Total age of two man  = (80+16) =96
Average age of those men = 96/2 = 48.
Hence, is 48 the required  average age.

Q 4 - What should be the average speed of the train if first 12 min. travelled by train at a speed of 30km/hr and after that speed increased and with the speed of 45km/hr travelled for next 8 min?

Answer : A

Explanation

Total covered distance by train = (30*12/60+45* 8/60) = 12 km
Total time taken by train  to cover the distance = 12+8 = 20min = 1/3 hours.
Required  average speed = 12*3/1 = 36 km/hr.

Q 5 - What should be the largest number if first number is the half of the second number and third number is 1/3 of the second number? 44 is the average of three numbers?

Answer : A

Explanation

if x is the third number , then second number = 3x  ∴ first number = 3x/2
Average =1/3 (3x/2+3x+x) ⇒  (11x/6) =44  ⇒ 11x=264 ⇒ x = 24
Hence, the second number (24*3)=72  is the largest number.

Q 6 - 555 is the sum of 5 numbers. What should be the last numbers if average of two numbers is 75 and last 3 numbers have average of 115?

Answer : A

Explanation

If a and b is the last two numbers. then,
 (75*2)+115+(a+b)= 555 ⇒(a+b)= 555-365= 290
 Average of last two numbers = 290/2 = 145

Q 7 - A grocer has a sale of Rs. 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must be have in the sixth month so that he gets an average sale of Rs. 6500?

Answer - D

Explanation

Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009. 
Therefore Required sale = Rs. [(6500 6) - 34009] = Rs. (39000 - 34009) = Rs. 4491

Q 8 - The average age of 15 students of a class is 15 years. Out of these, the average age of 5 5 students is 14 years and that of the other 9 students is 16 years. The age of the 15th student is?

Answer - A

Explanation

Age of the 15th student = [15 x 15 - (14 x 5 + 16 x 9)] = (225 - 214) = 11 years.

Q 9 - The average age of 36 students in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years?

Answer - D

Explanation

Age of the teacher = (37 x 15 - 36 x 14) years = 51 years.

Q 10 - The average weight of 3 men A, B, C is 84 kg. Another man D joins the group and the average now becomes 80kg. If another man E, whose weight is 3 kg more than that of D, replaces A, then the average weight of B, C, D, E becomes 79kg. The weight of A is?

Answer - B

Explanation

Let A, B, C, D and E represent their respective weights. Then, 
A + B + C = (84 x 3) = 252 kg, 

A + B + C + D = (80 x 4) = 320 kg. 
D = (320 - 252)kg = 68 kg, 
E = (68 + 3)kg = 71 kg. 

B + C + D + E =  (79 x 4) = 316 kg 
Now, (A + B + C + D) - (B + C + D + E) = (320 - 316)kg = 4 kg 
 
A - E = 4 
A = ( 4 + E ) = 75 kg.

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