1. A Volvo tourist bus with only the driver inside has a speed of 80 kmph. Its maximum speed reduces by a quantity that is directly proportional to the number of passengers (excluding the driver) seated inside. The maximum speed of the bus reduces by 20 kmph, if there are 5 passengers. A maximum of how many passengers should be seated so that the bus can move?
Answer: Option B
Explanation:
If R is the reduction in maximum speed and N is the number of passengers, then R is proportional to N
⇒ R = NK where K is constant of proportionality,
Given data: R = 20, when N = 5, hence K = 4
Maximum number of passenger that bus can’t move = (80 – N × K) = 80 – N × 4 ⇒ N = 20
So number of passenger for bust just move = 20 – 1 = 19
2. In an exam of 100 marks, the average marks of a class of 40 students are 76. If the top 3 scorers of the class leave, the average score falls “down by 1. If the other two toppers except “the highest topper scored not more than 85. “then what is the minimum score the topper can score?
Answer: Option C
Explanation:
Total score of 40 students = (40 × 76) = 3040
Total score of top 3 scorers = 3040 – (37 × 75) = 265
To minimize the score of the top scorer, we assume the other two top scorers score the maximum they can = 85 marks each.
So, the top scorer scored = 265 – 170 = 95 marks.
3. The average weight of three friends Amar, Visera, and Daman is 70 kg. Another person Vishal joins the group and now the average is 66 kg. If another person Tahir whose weight is 6 kg more than Vishal, joins the group replacing Amar, then the average weight of Visera, Daman, Vishal, and Tahir becomes 75 kg. What is the weight of Amar (in kg)?
Answer: Option D
Explanation:
Total weight of Amar, Visera and Daman = 70 × 3 = 210 kg
Again, Amar + Visera + Daman + Vishal = 66 × 4 = 264 kg ......... (i)
∴ Weight of Vishal = 264 – 210 = 54 kg
∴ Weight of Tahir = 54 + 6 = 60 kg
Now, as per the question
Visera + Daman + Vishal + Tahir = 75 × 4 = 300 kg. ................... (ii)
Subtracting (i) from (ii), we get
Tahir – Amar = 60 – Amar = 300 – 264 = 36
Therefore, weight of Amar = 60 – 36 = 24 kg
4. The average salary of a company increases by 100 when the salary of the manager, which is Rs. 9500, is included. If the number of employees excluding the manager is the smallest cube divisible by 16, what is the final average of the company?
A. Rs. 4000
B. Rs. 3400
C. Rs. 3700
D. Rs. 3100
Answer: Option D
Explanation:
The smallest cube divisible by 16 is 64.
Let's assume the average salary before the manager's salary is included is x
After addition of the Manager's salary the average increases by 100
We can write down the above information in form of an equation as:
64x + 9500 = 65 × (x + 100)
Solving for x, we get x = 3000
The final average is 3000 + 100 = Rs. 3100
5. An exam was conducted in a state over 222 centers. The average number of applicants percenter was found to be 1560. However, it was later realized that in one center, the number of applicants was counted as 1857 instead of 1747. What was the correct average number of applicants per center (up to two decimals)?
A. 1557.87
B. 1558.20
C. 1558.92
D. 1559.51
Answer: Option D
Explanation:
Number of applicants that have been counted extra = 1857 − 1747 = 110
Hence, decrease in average = [latex]\frac {110}{22}[/latex] = 0.495
∴ Correct average = 1560 − 0.495 = 1559.505 = 1559.51