Arithmetic Mcqs - Set 1

1)   Masood purchased a plot for Rs. 8,000. He sells the plot to Aftab at a profit of 20%. Aftab in turn sells that plot to Zahid at a loss of 20%. The plot costs Zahid ?

a. Rs. 12,000
b. Rs. 10,000
c. Rs. 8670
d. Rs. 7680
Answer  Explanation 

ANSWER: Rs. 7680

Explanation:
8000 x 20 / 100 = 1600 (so Masood earns 1600 profit (20%)

Aftab Purchase plot at 8000 + (20% which is 1600 ) = 9600

20% of 9600 = 1920 (Loss of Aftab)

So The plot costs Zahid: 9600 -1920 = 7680


2)   If a car is sold for Rs..50000 the profit is 17 percent, what would be profit percentage if sold for Rs. 47000?

a. 14.85%
b. 9.98%
c. 16.20%
d. 14.50%
Answer  Explanation 

ANSWER: 9.98%

Explanation:
No explanation is available for this question!


3)   If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:

a. 53.33
b. 54.68
c. 55
d. None of these
Answer  Explanation 

ANSWER: 54.68

Explanation:
55 students get average marks of 55%.
so 55*50=2750
similarly 60*55=3300
& 60*45=2700
now total no of marks obtain by all students of three batches= 2750+3300+2700=8750/=
Total no of students= 55+60+45=160.
By dividing total marks on each student , we get average marks obtain by each student
so 8750/160 = 54.68


4)   Two automobiles are 150 kilometers apart and traveling toward each other. One automobile is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet?

a. 2.5
b. 2.0
c. 1.75
d. 1.5
e. 1.25
Answer  Explanation 

ANSWER: 1.5

Explanation:
One moves at 60km/h, so in an hour, he’ll travel 60km
The other moves at 40km/h, so in an hour, he’ll travel 40km
This is towards each other, so, in an hour, we can say that they’ll get 60+40=100km closer.

This means that they get closer at 100km/h

Given that we have the distance of 150km, and the speed of closure at 100kmh, we can now use the equation

S=D/T

Rearrange to find T (times both sides by T)

S x T = D (now divide both sides by S)

T=D/S

Time = 150km divided by 100km/h

Time = 1.5 hours

Or one hour and 30 minutes


5)   The average of first 10 even numbers is___________?

a. 18
b. 22
c. 9
d. 11
Answer  Explanation 

ANSWER: 11

Explanation:
No explanation is available for this question!


6)   The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is 11.4 the sixth number is_____________?

a. 11.0
b. 11.3
c. 11.4
d. 11.5
Answer  Explanation 

ANSWER: 11.5

Explanation:
Sum of 11 numbers = 11×10.9 = 119.9
Sum of 1st 6 numbers = 6×10.5 = 63
So, sum of last 5 numbers = 119.9-63 = 56.9
And sum of last 6 numbers = 6×11.4 = 68.4
Hence sixth number will be = 68.4-56.9= 11.5


7)   The average of first ten prime numbers which are odd is____________?

a. 12.9
b. 13.8
c. 15.8
d. 17
Answer  Explanation 

ANSWER: 15.8

Explanation:
The odd primes :-

3 , 5 , 7 , 11 , 13 , 17 , 19 , 23 , 29 , 31

Average = 3+5+7+11+13+17+19+23+29+31/10

= 158/10

= 15.8


8)   The average of first 10 natural numbers is____________?

a. 5
b. 5.5
c. 6.5
d. 6
Answer  Explanation 

ANSWER: 5.5

Explanation:
Sum of 10 natural no. = 110/2 = 55

Average = 55/10 = 5.5


9)   The average of first 10 odd numbers is_____________?

a. 11
b. 10
c. 12
d. 17
Answer  Explanation 

ANSWER: 10

Explanation:
Sum of 10 odd no. = 100

Average = 100/10 = 10


10)   The average age of three boys is 15 years and their ages are in proportion 3:5:7. What is the age in years of the youngest boy?

a. 15
b. 9
c. 18
d. 21
Answer  Explanation 

ANSWER: 9

Explanation:
3x + 5x + 7x = 45

x =3

3x = 9