TCS Questions on Ratio, Proportion and Averages with Answers – 1

1.The average temperature of Tuesday Wednesday and Thursday was 37 C. The average temperature of Wednesday and Thursday and Friday was 38 C. if the temperature on Friday was 39 C.
Find the temperature on Tuesday.
a. 37.33
b. 38.33
c. 36
d. None of the above
Explaination: (Tues + Wed + Thurs)/3=37
Tues + Wed + Thurs=111…(1)
(Wed + Thurs + Fri)/3=38
(Wed + Thurs + Fri) =114…(2)
Given friday is 39.
Then, (2) – (1) Fri – Tues = 3
So 39 – Tues = 3
Tuesday =36

2.There are 5 boxes in a cargo. The weight of the 1st box is 200 KG, the weight of the 2nd box is 20% higher than the third box, whose weight is 25% higher than the 1st box weight. The 4th box which weighs 350 KG is 30% lighter than the 5th box. Find the difference in average weight of the 4 heaviest boxes and the four lightest boxes.
Explaination: weight of 1st box=200
weight of 3rd box=(125/100)*200=250
aweight of 2nd box=(120/100)*250=300
weight of 4th box =350
weight of 5th box=(10/7)*350=500
average of 4 highest weighted boxes=(500+350+300+250)/4=350
average of 4 lightest boxes=(350+300+250+200)/4=275
therefore difference=350-275=75

3. Anusha, Banu and Esha run a running race of 100 meters. Anusha is the fastest followed by Banu and then Esha. Anusha, Banu and Esha maintain constant speeds during the entire race. When Anusha reached the goal post, Banu was 10m behind. When Banu reached the goal post Esha was 10m behind. How far was behind Anusha when the latter reached the goal post.
Explaination:By that time Anusha covered 100m, Bhanu covered 90m. So ratio of their speeds = 10 : 9
By that time Bhanu reached 100m, Esha covered 90m. So ratio of their speeds = 10 : 9
Ratio of the speed of all the three = 100 : 90 : 81
By that time Anusha covered 100m, Esha Covers only 81.

4.The savings of employee equals income minus expenditure.If the income of A,B,C are in the ratio 1:2:3 and their expense ratio 3:2:1 then what is the order of the employees in increasing order of their size of their savings?
Ans: A < B < C
Explaination: As the the ratio of their incomes are in ascending order, and their expenses are in descending order, their savings also in their incomes order.
So savings order = A < B < C

5.Seats for Mathematics, Physics and Biology in a school are in the ratio 5 : 7 : 8. There is a proposal to increase these seats by 40%, 50% and 75% respectively. What will be the ratio of increased seats?
a.2 : 3 : 4
b.6 : 7 : 8
c.6 : 8 : 9
d.None of these
Answer: Option A
Explanation: Originally, let the number of seats for Mathematics, Physics and Biology be 5x, 7x and 8x respectively.
Number of increased seats are (140% of 5x), (150% of 7x) and (175% of 8x).

6.If 0.75 : x :: 5 : 8, then x is equal to:
Answer: Option B
(x x 5) = (0.75 x 8) x =6/5 = 1.20

7.The fourth proportional to 5, 8, 15 is:
Answer: Option B
Explanation: Let the fourth proportional to 5, 8, 15 be x.
Then, 5 : 8 : 15 : x
5x = (8 x 15)
x = (8/5x 15)= 24.

8.In a bag, there are coins of 25 p, 10 p and 5 p in the ratio of 1 : 2 : 3. If there is Rs. 30 in all, how many 5 p coins are there?
Answer: Option C
Explanation: Let the number of 25 p, 10 p and 5 p coins be x, 2x, 3x respectively.