1. 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?
A. Rs. 4991
B. Rs. 5991
C. Rs. 6001
D. Rs. 6991
Answer - Option A
Explanation -
Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009.
i.e, Required sale = Rs. [ (6500 x 6) - 34009 ]
= Rs. (39000 - 34009)
= Rs. 4991.
2. The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Answer - Option D
Explanation -
Average of 20 numbers = 0.
i.e, Sum of 20 numbers (0 x 20) = 0.
It is quite possible that 19 of these numbers may be positive and if their sum is a then 20th number is (-a).
3. The average weight of 8 person's increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?
A. 76 kg
B. 76.5 kg
C. 85 kg
D. None of these
Answer - Option C
Explanation -
Total weight increased = (8 x 2.5) kg = 20 kg.
Weight of new person = (65 + 20) kg = 85 kg.
4. The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
A. 8 : 9
B. 17 : 18
C. 21 : 22
D. None the these
Answer - Option C
Explanation -
Originally, let the number of boys and girls in the college be 7x and 8x respectively.
Their increased number is (120% of 7x) and (110% of 8x).
[latex]\Rightarrow (\frac {120}{100} \times 7x) [/latex]and [latex](\frac {110}{100} \times 8x)[/latex]
[latex]\Rightarrow \frac {42x}{5}[/latex] and [latex] \frac {44x}{5} = 21 : 22[/latex]
i.e, The required ratio = [latex](\frac {42x}{5} : \frac {44x}{5})[/latex] = 21 : 22
5. Salaries of Ravi and Sumit are in the ratio 2 : 3. If the salary of each is increased by Rs. 4000, the new ratio becomes 40 : 57. What is Sumit's salary?
A. Rs. 17,000
B. Rs. 20,000
C. Rs. 25,500
D. Rs. 38,000
Answer - Option D
Explanation -
Let the original salaries of Ravi and Sumit be Rs. 2x and Rs. 3x respectively.
Then, [latex]\frac {2x + 4000}{3x + 4000} = \frac {40}{57}[/latex]
[latex]\Rightarrow[/latex] 57(2x + 4000) = 40(3x + 4000)
[latex]\Rightarrow[/latex] 6x = 68,000
[latex]\Rightarrow[/latex] 3x = 34,000
Sumit's present salary = (3x + 4000) = Rs.(34000 + 4000) = Rs. 38,000.