Computation of whole numbers:
1. Which one of the following is not a prime number?
Answer: Option D
Explanation:
91 is divisible by 7. So, it is not a prime number.
Decimals:
1. 3889 + 12.952 - ? = 3854.002
A. 47.095
B. 47.752
C. 47.932
D. 47.95
Answer: Option D
Explanation:
Let 3889 + 12.952 - x = 3854.002.
Then x = (3889 + 12.952) - 3854.002
= 3901.952 - 3854.002
= 47.95.
Fractions and relationships between numbers:
1. Three times the first of three consecutive odd integers is 3 more than twice the third. The third integer is:
Answer: Option D
Explanation:
Let the three integers be x, x + 2 and x + 4.
Then, 3x = 2(x + 4) + 3
x = 11.
Third integer = x + 4 = 15.
Percentage:
1. In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 7500, the number of valid votes that the other candidate got, was:
A. 2700
B. 2900
C. 3000
D. 3100
Answer: Option A
Explanation:
Number of valid votes = 80% of 7500 = 6000.
Valid votes polled by other candidate = 45% of 6000
=[latex]\frac{45}{100}[/latex]*6000 = 2700
Ratio & Proportion:
1. If 0.75 : x :: 5 : 8, then x is equal to:
A. 1.12
B. 1.2
C. 1.25
D. 1.30
Answer: Option B
Explanation:
(x x 5) = (0.75 x 8)
x =[latex]\frac{6}{5}[/latex]
x= 1.20
Square roots:
1. How many two-digit numbers satisfy this property.: The last digit (unit's digit) of the square of the two-digit number is 8 ?
A. 1
B. 2
C. 3
D. None of these
Answer: Option D
Explanation:
A number ending in 8 can never be a perfect square
Averages:
1. 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).
Simple Interest:
1. How much time will it take for an amount of Rs. 450 to yield Rs. 81 as interest at 4.5% per annum of simple interest?
A. 3.5 years
B. 4 years
C. 4.5 years
D. 5 years
Answer: Option B
Explanation:
Then = ([latex]\frac{100 x 81}{450 x 4.5}[/latex])= 4 years.
Compound Interest:
1. What will be the compound interest on a sum of Rs. 25,000 after 3 years at the rate of 12 p.c.p.a.?
A. Rs. 9000.30
B. Rs. 9720
C. Rs. 10123.20
D. Rs. 10483.20
E. None of these
Answer: Option C
Explanation:
Amount = Rs.[25000*(1+[latex]\frac{12}{100})^{3}[/latex]]
= Rs.[25000*[latex]\frac{28}{25}[/latex]*[latex]\frac{28}{25}[/latex]*[latex]\frac{28}{25}[/latex]]
= Rs. 35123.20
C.I. = Rs. (35123.20 - 25000) = Rs. 10123.20
Profit and Loss:
1. The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25%, then the value of x is:
Answer: Option B
Explanation:
Let C.P. of each article be Re. 1 C.P. of x articles = Rs. x.
S.P. of x articles = Rs. 20.
Profit = Rs. (20 - x).
([latex]\frac{20 - x}{x}[/latex]*100)= 25
2000 - 100x = 25x
125x = 2000
x = 16.
Discount:
1. Rs. 20 is the true discount on Rs. 260 due after a certain time. What will be the true discount on the same sum due after half of the former time, the rate of interest being the same?
A. Rs. 10
B. Rs. 10.40
C. Rs. 15.20
D. Rs. 13
Answer: Option B
Explanation:
S.I. on Rs. (260 - 20) for a given time = Rs. 20.
S.I. on Rs. 240 for half the time = Rs. 10.
T.D. on Rs. 250 = Rs. 10.
T.D. on Rs. 260 = Rs.([latex]\frac{10}{250}[/latex]*260) = Rs. 10.40
Partnership Business:
1. A, B, C subscribe Rs. 50,000 for a business. A subscribes Rs. 4000 more than B and B Rs. 5000 more than C. Out of a total profit of Rs. 35,000, A receives:
A. Rs. 8400
B. Rs. 11,900
C. Rs. 13,600
D. Rs. 14,700
Answer: Option D
Explanation:
Let C = x.
Then, B = x + 5000 and A = x + 5000 + 4000 = x + 9000.
So, x + x + 5000 + x + 9000 = 50000
3x = 36000
x = 12000
A : B : C = 21000 : 17000 : 12000 = 21 : 17 : 12.
A's share = Rs.(35000*[latex]\frac{21}{50}[/latex])= Rs. 14,700.
Mixture and Alligation:
1. Find the ratio in which rice at Rs. 7.20 a kg be mixed with rice at Rs. 5.70 a kg to produce a mixture worth Rs. 6.30 a kg.
A. 1 : 3
B. 2 : 3
C. 3 : 4
D. 4 : 5
Answer: Option B
Explanation:
By the rule of alligation:
Required ratio = 60 : 90 = 2 : 3.
Time and distance:
1. A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot @ 4 km/hr and partly on bicycle @ 9 km/hr. The distance travelled on foot is:
A. 14 km
B. 15 km
C. 16 km
D. 17 km
Answer: Option C
Explanation:
Let the distance travelled on foot be x km.
Then, distance travelled on bicycle = (61 -x) km.
So,[latex]\frac{x}{4}[/latex]+([latex]\frac{61-x}{9}[/latex])= 9
9x + 4(61 -x) = 9 x 36
5x = 80
x = 16 km.
Time & Work:
1. Sakshi can do a piece of work in 20 days. Tanya is 25% more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work is:
Answer: Option B
Explanation:
Ratio of times taken by Sakshi and Tanya = 125 : 100 = 5 : 4.
Suppose Tanya takes x days to do the work.
5 : 4 :: 20 : x =[latex]\frac{4 × 20}{5}[/latex]
x = 16 days.
Hence, Tanya takes 16 days to complete the work.