Averages

Aptitude Solved Problems: AVERAGES
Questions :

1. 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?

2. A batsman makes a score of 87 runs in the 17th match and thus increases his average by 3. Find his average after 17th match?

3. 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 he have in the sixth month so that he gets an average sale of Rs. 6500?

Answers :

1. Answer : 40 years.

2. Answer: 39.

3. Answer: Rs. 4991.

1. Explanation:

Sum of the present ages of husband, wife and child
= (27 * 3 + 3 * 3) years = 90 years.
Sum of the present ages of wife and child
= (20 * 2 + 5 * 2) years = 50 years.
Husband′s present age
= (90 – 50) years
= 40 years

∴ The present age of the husband is 40 years.

2. Explanation:

Let the average after 17 innings = x
Total runs scored in 17 innings = 17x
then average after 16 innings = (x – 3)
Total runs scored in 16 innings = 16 (x – 3)
We know that Total runs scored in 16 innings + 87 = Total runs scored in 17 innings
⇒ 16(x – 3) + 87 = 17x
⇒ 16x – 48 + 87 = 17x
⇒ x = 39

∴ The average after 17th match is 39.

3. Explanation:

Total sale for 5 months is
= Rs. ( 6435 + 6927 + 6855 + 7230 + 6562 )
= Rs. 34009.
Required sale = Rs. [ (6500 * 6) – 34009 ]
= Rs. (39000 – 34009)
= Rs. 4991.

∴ The average sale is Rs. 4991.