Practice Aptitude Questions (Arithmetic) With Solutions

Practice Aptitude Questions (Arithmetic
Practice Aptitude Questions (Arithmetic) With Solutions Set-57:
Dear Readers, Important Aptitude Questions for SSC/FCI Exam was given here with solutions, candidates those who are preparing for those exams can use this material.


1).A bag contains 1 – rupee, 50 – paise and 25 paise coins in the ratio of 3 : 4 : 4. If the total amount is Rs. 90, the number of 1 rupee coins is
a)    30
b)    15
c)    45
d)    60

2).A jar contains 40 white and 120 black marbles. How many white marbles must be added to the jar so that 50% of the marbles become white?
a)    80
b)    60
c)    50
d)    40

3).A and B can do a piece of work in 12 days, B and C can do it in 18 days, C and A can do it in a 20 days. The time taken by A, B and C together to do the same piece of work will be
a)    12 (10/17) days
b)    10 (1/17) days
c)    10 (10/17) days
d)    13 (10/17) days

4).40 men can finish a work in 80 days, working 10 hours per day. How many men can finish the same work in 20 days, working 8 hours per day?
a)    400 men
b)    200 men
c)    600 men
d)    100 men

5).Two pipes A and B can fill a tank in 12 hours and 15 hours respectively and C can empty it in 10 hours. If all three pipes are opened at 5 : 30 am, at what time will half of the tank be filled
a)    3 : 30 pm
b)    3 : 20 am
c)    3 : 00 pm
d)    5 : 30 pm

6).The radius of a wheel is 84 cm. it completes 600 rotations in 10 minutes. What is its speed ( in kmph)?
a)    28
b)    24.008
c)    19.008
d)    16

7).The speed of stream is 6 Kmph. A motor boat goes 12 km upstream and comes back to the starting point in 90 minutes. The speed of the motorboat ( in kmph ) in still water is
a)    22
b)    16
c)    18
d)    12

8).Water flowing at the rate of 10 kmph through a pipe of diameter 28 cm into a rectangular tank which is 100 m and long and 88m wide. The time taken ( in hours ) for 14 cm rise in water level in the tank will be
a)    8 hours
b)    6 hours
c)    4 hours
d)    2 hours

9).The mean of 15 numbers is 40. Later on, it was observed that 25 and 15 were wrongly taken as 52 and 51. The correct mean is
a)    33.8
b)    35.8
c)    38.5
d)    36.0

10).The product of two numbers is 4056 and their HCF is 26. The number of such pairs is
a)    1
b)    2
c)    3
d)    4

Answers:                         
1).c)  2). a) 3). c) 4).b)  5).a)  6). c) 7). c) 8). c) 9).b)  10).b)

Solution:
1). Let the numbers of coins be 3x, 4x and 4x respectively,
            Then, the value of coins = (3x / 1) + (4x / 2) + (4x / 4)
            = 3x + 2x + x = 6x
            Given 6x = 90
            ∴ x = 15
            Number of 1 rupee coins = 3x = 3 × 15 = 45
Answer: c )
2). Suppose x white marbles are added.
            Then, (x + 40) / 120 = 50 / 50
            Or, x + 40 – 120
            Or, x = 80
Answer: a )
3). (A + B) can do 1/12 work in 1 day,
            Again B + C can do 1/18 work in 1 day,
            And C + A can do 1/20 work in 1 day.
            Now, 2 (A + B + C)’s 1 day’s work
            = (1/12) + (1/18) + (1/20) = (30 + 20 + 18) / 360 = 68 / 360
            ∴ ( A + B + C)’s 1 day’s work = 68 / 720
            Hence A, B and C will complete the work in 180/17  = 10 (10/17) days
Answer: c)
4). 40 men, working 10 hours a day can do a piece of work in 80 days.
            Suppose x men can do the same piece of work in 20 days, working 8 hours a day,
            Now, M1 D1 H1 = M2 D1 H2
            ∴ 40 × 80 × 10 = x × 20 × 8
            x = (40 × 80 × 10) / (20 × 8) = 200 men
Answer: b )
5). A and B can fill the tank in 12 and 15 hours respectively
            C can empty the tank in 10 hours,
            So, A, B, and C can fill in 1 hour
            (1 / 12) + (1 / 15) – (1 / 10) = (5 + 4 – 6) / 60 = 3 / 60 = 1 / 20
            All three pipes are opened at 5 : 30 am.
            ∴ they will fill 1 / 2 of the tank in
            (1 / 2) × 20 = 10 hours from 5 : 30 am
            ∴ Time = 5 : 30 am + 10 hours = 15 : 30
            = 3 : 30 pm
Answer: a )
6). Radius of the wheel is 84 cm.
            ∴ Circumference of the wheel = 2
            = 2 × (22 / 7) × 84 = 528 cm
            ∴ Distance covered in 10 minutes
            = 528 × 600 = 316800 cm = 3.168 km (100 cm = 1 m and 1000 m = 1 km)
            ∴ Time = 10 mnutes = 10 / 60 hours = 1 / 6 hours
            ∴ Speed = Distance / Time = 3168 / (1/6) kmph
            = 19.008 kmph
Answer: c)
7). Speed of the current = 6 kmph
            Let the speed of motorboat in still water be x kmph
            Speed downstream = ( x + 6) kmph
            Speed upstream = ( x – 6) kmph
            Now, according to the question,
            [12 / (x – 6)] + [12 / (x + 6)] = 90 / 60 = 3 / 2
            Or, (12x + 72 + 12x – 72) / (x2 – 36) = 3 / 2
            Or, 24x / (x2 – 36) = 3 / 2
            Or, x2 – 16x – 36 = 0
            Or, x2 – 18x + 2x – 36 = 0
            Or, x(x – 18) + 2(x – 18) = 0
            Or,(x – 18) (x + 2) = 0
            x = 18 kmph
            ∴ Neglect negative value
Answer: c)
8). Volume of water = 100 × 88 × 14 × 100 × 100 cm3
                ∴ Volume of water filled in 1 hour
            = ( 22/7) × 14 × 14 × 10000 × 100 cm3
            Reqd time = (10000 × 8800 × 14) / [(22/7) × 14 × 14 × 1000000 ]
            = 4 hours       
Answer: c )
9). The wrong sum = 15 × 40 = 600
            The correct sum = 600 – ( 52 + 51 ) + ( 25 + 15) = 600 + 40
            103 = 537
            The correct mean = 537 / 15 = 35.8
Answer: c)
10). HCF of two numbers is 26
Let the numbers be 26a and 26b
∴ 26a × 26b = 4056
ab = 4056 / (26×26) = 6
(a, b) = ( 1,6) (2,3)
So required numbers are ( 26 × 1, 26 × 6) and ( 26 × 2, 26 × 3)
Number of such pairs = 2
Answer: b)