Percentage
1. The tax on a commodity is diminished by 20% but its consumption is increased by 10%. Find the decrease percent in the revenue derived from it?
A. 20%
B. 18%
C. 15%
D. 12%
Answer: Option (D)
Explanation:
100 * 100 = 10000
80 * 110 = 8800
10000------- 1200
100 ------- ? = 12%
2. At an examination in which full marks were 500. A got 10% less than B, B got 25% more than C and C got 20% less than D. If A got 360marks, what percentage of full marks was obtained by D?
A. 70%
B. 90%
C. 80%
D. 75%
Answer: Option (C)
Explanation:
A B C D
90 100 80 100
A D
90 ----- 100
360 ------ ? = 400
500 ------ 400
100 ------- ? => 80%
3. If the population of a certain city increases at a rate of 5%. If the population in 1981 was 138915, then the population in 1978 was?
A. 1,20,000
B. 1,10,000
C. 1,00,000
D. 90,000
Answer: Option (A)
Explanation:
X * (105/100) * (105/100) * (105/100) = 138915
X = 138915/1.157625
X = 120000
4. There were two candidates in an election. Winner candidate received 62% of votes and won the election by 288 votes. Find the number of votes casted to the winning candidate?
A. 456
B. 744
C. 912
D. 1200
Answer: Option (B)
Explanation:
W = 62% L = 38%
62% - 38% = 24%
24% -------- 288
62% -------- ? => 744
5. A man spends 10% of his income in house rent, 20% of the rest on his children’s education, 25% of the rest miscellaneous causes. If he now posses Rs. 1944 then his income is?
A. Rs.3600
B. Rs.4000
C. Rs.4500
D. Rs.3000
Answer: Option (A)
Explanation:
X * (90/100) * (80/100) * (75/100) = 1944
X * 0.9 * 0.8 * 0.75
X = 1944/0.54
X = 3600
Number System
1. When writing numbers from 1 to 10,000, how many times is the digit 9 written?
A. 3200
B. 3600
C. 4000
D. 4200
Answer: Option(C)
Explanation:
The digits 9 occurs in the thousands place in 1000 numbers.
It occurs in the hundreds place in 1000 numbers and so on
The digit occurs 4000 times.
2. Which digits should come in place of @ and # if the number 62684@# is divisible by both 8 and 5?
A. 4, 0
B. 0, 4
C. 4, 4
D. 1, 1
Answer: Option (A)
Explanation:
Since the given number is divisible by 5, so 0 or 5 must come in place of #.
But, a number ending with 5 is never divisible by 8.
So, 0 will replace #.
Now, the number formed by the last three digits is 4@0, which becomes divisible by 8, if @ is replaced by 4.
Hence, digits in place of @ and # are 4 and 0 respectively.
3. How many keystrokes are needed to type numbers from 1 to 1000 on a standard keyboard?
A. 3001
B. 2893
C. 2704
D. 2890
Answer: Option (B)
Explanation:
While typing numbers from 1 to 1000, you have 9 single digit numbers from 1 to 9. Each of them requires one keystroke. That is 9 keystrokes.
There are 90 two-digit numbers, from 10 to 99. Each of these numbers requires 2 keystrokes. Therefore, one requires 180 keystrokes to type the 2 digit numbers.
There are 900 three-digit numbers, from 100 to 999. Each of these numbers requires 3 keystrokes. Therefore, one requires 2700 keystrokes to type these 3 digit numbers.
Then 1000 is a four-digit number which requires 4 keystrokes.
Totally, therefore, one requires 9+180+2700+4= 2893 keystrokes.
4. How many natural numbers below 660 are divisible by 5 and 11 but not by 3?
Answer: Option (A)
Explanation:
If the number is divisible by 5 and 11 it must be divisible by 55.
The numbers are less than 660.
Hence, dividing 659 by 55 gives the number of multiples of 55 = 11 (ignoring fraction part).
The 11 multiples of 55 which are less than 560, but of these 11 multiples some can be multiples of 3.
The numbers of such, multiples are the quotient of 11 by 3.
Quotient of [latex]\frac {11}{3}[/latex] = 3.
Out of 11 multiples of 55, 3 are multiples of 3.
Hence, numbers less than 660 and divisible by 5 and 11 but not by 3=11−3=8
5. What is the maximum value of m such that 7m divides into 14! evenly?
Answer: Option(B)
Explanation:
The term 14! equals the product of the numbers 1,2,3,4,5,6,7,8,9,10,11,12,13 and 14.
Only two of these numbers are divisible by 7.
The numbers are 7 and 14.
Hence, 14! can be expressed as the product of k×7×14, where k is not divisible by 7.
Now, since there are two 7s in 14!, the numbers 7 and 7[latex]^{2}[/latex] divides 14! evenly.
7[latex]^{3}[/latex] and further powers of 7 leave a remainder when divided into 14!.
Hence, the maximum value of m is 2.
Average
1. The captain of a cricket team of 11 members is 26 years old and the wicketkeeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team?
A. 23 years
B. 24 years
C. 25 years
D. None of these
Answer: Option (A)
Explanation:
Let the average age of the whole team by x years.
11x - (26 + 29) = 9(x -1)
11x - 9x = 46
2x = 46
x = 23.
So, the average age of the team is 23 years.
2. The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R are Rs. 5200. The monthly income of P is:
A. 3500
B. 4000
C. 4050
D. 5000
Answer: Option (B)
Explanation:
Let P, Q and R represent their respective monthly incomes. Then, we have:
P + Q = (5050 x 2) = 10100 .... (i)
Q + R = (6250 x 2) = 12500 .... (ii)
P + R = (5200 x 2) = 10400 .... (iii)
Adding (i), (ii) and (iii), we get: 2(P + Q + R) = 33000 or P + Q + R = 16500 .... (iv)
Subtracting (ii) from (iv), we get P = 4000.
P's monthly income = Rs. 4000.
3. 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:
A. 35 years
B. 40 years
C. 50 years
D. None of these
Answer: Option (B)
Explanation:
Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.
Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.
Husband's present age = (90 - 50) years = 40 years.
4. 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.
Required sale = Rs. [(6500 x 6) - 34009]
= Rs. (39000 - 34009)
= Rs. 4991.
5. 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.
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).
Number Series
1. 42 40 38 35 33 31 28
A. 25 22
B. 26 23
C. 26 24
D. 25 23
E. 26 22
Answer: Option (C)
Explanation:
This is an alternating subtraction series in which 2 is subtracted twice, then 3 is subtracted once, then 2 is subtracted twice, and so on.
2. 6 10 14 18 22 26 30
A. 36 40
B. 33 37
C. 38 42
D. 34 36
E. 34 38
Answer: Option (E)
Explanation:
This simple addition series adds 4 to each number to arrive at the next.
3. 8 12 9 13 10 14 11
A. 14 11
B. 15 12
C. 8 15
D. 15 19
E. 8 5
Answer: Option (B)
Explanation:
This is an alternating addition and subtraction series, in which the addition of 4 is alternated with the subtraction of 3.
4. 36 31 29 24 22 17 15
A. 13 11
B. 10 5
C. 13 8
D. 12 7
E. 10 8
Answer: Option (E)
Explanation:
This is an alternating subtraction series, which subtracts 5, then 2, then 5, and so on.
5. 3 5 35 10 12 35 17
A. 22 35
B. 35 19
C. 19 35
D. 19 24
E. 22 24
Answer: Option (C)
Explanation:
This is an alternating addition series, with a random number, 35, interpolated as every third number. The pattern of addition is to add 2, add 5, add 2, and so on. The number 35 comes after each "add 2" step.
Ratio and Percentage
1. A sum of money is to be distributed among A, B, C, D in the proportion of 5 : 2 : 4 : 3. If C gets Rs. 1000 more than D, what is B's share?
A. Rs. 500
B. Rs. 1500
C. Rs. 2000
D. None of these
Answer: Option (C)
Explanation:
Let the shares of A, B, C, and D be Rs. 5x, Rs. 2x, Rs. 4x and Rs. 3x respectively.
Then, 4x - 3x = 1000
x = 1000.
B's share = Rs. 2x = Rs. (2 x 1000) = Rs. 2000.
2. 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}[/latex] = [latex]\frac {40}{57}[/latex]
57(2x + 4000) = 40(3x + 4000)
6x = 68,000
3x = 34,000
Sumit's present salary = (3x + 4000) = Rs.(34000 + 4000) = Rs. 38,000.
3. If 40% of a number is equal to two-thirds of another number, what is the ratio of the first number to the second number?
A. 2: 5
B. 3: 7
C. 5: 3
D. 7: 3
Answer: Option (C)
Explanation:
Let 40% of A = [latex]\frac {2}{3}[/latex] B
Then,[latex]\frac {40A}{100}[/latex] = [latex]\frac {2B}{3}[/latex]
[latex] \frac{2A}{5}[/latex] = [latex]\frac {2B}{3}[/latex]
[latex]\frac {A}{B}[/latex] = [latex]\frac{2}{3}[/latex] x [latex]\frac {5}{2}[/latex] = [latex]\frac {5}{3}[/latex]
A : B = 5 : 3.
4. Two number are in the ratio 3: 5. If 9 is subtracted from each, the new numbers are in the ratio 12: 23. The smaller number is:
Answer: Option (B)
Explanation:
Let the numbers be 3x and 5x.
Then, [latex]\frac {3x - 9}{5x - 9}[/latex] = [latex]\frac {12}{23}[/latex]
23(3x - 9) = 12(5x - 9)
9x = 99
x = 11.
The smaller number = (3 x 11) = 33.
5. The greatest ratio out of 2:3, 5:4, 3:2 and 4:5 is?
A. 4:5
B. 3:2
C. 5:4
D. 2:3
Answer: Option (B)