Arithmetic Mcqs

A. 9
B. 17
C. 29
D. 295
Explanation:
Let the number be x. Then,
(x + x2)/2 = 5x => x2 – 9x = 0
=> x(x – 9) = 0
=> x = 0 or x = 9
So, the number is 9

A. 33
B. 44
C. 55
D. 66
Explanation:
Average = (11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99)/9
= [(11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55]/9
= [(4 * 110) + 55]/9 = 495/9 = 55

A. 3
B. 9
C. 12
D. 15
Explanation:
Average = 3(1 + 2 + 3 + 4 + 5)/5 = 45/5 = 9

A. 18
B. 20
C. 24
D. 30
Explanation:
Average = (10 + 15 + 20 + 25 + 30)/5 = 100/5 = 20

A. 0
B. 1
C. 10
D. 19
Average of 20 numbers = 0
Sum of 20 numbers = (0 * 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).

A. 65
B. 69
C. 72
D. None of these
Average = (76 + 65 + 82 + 67 + 85)/5 = 375/5 = 75

A. 70, 50
B. 60, 60
C. 50, 70
D. 40, 80
Let the number of boys be x.
Number of girls is 120 – x.
Total number of chocolates received by boys and girls = 2x + 3(120 – x) = 300
=> 360 – x = 300 => x = 60.
So, the number of boys or girls is 60

A. 5 : 1
B. 4 : 1
C. 3 : 2
D. 2 : 1
Let the amount lent at 7% be Rs. x
Amount lent at 10% is Rs. (6000 – x)
Total interest for one year on the two sums lent
= 7/100 x + 10/100 (6000 – x) = 600 – 3x/100
=> 600 – 3/100 x = 450 => x = 5000
Amount lent at 10% = 1000
Required ratio = 5000 : 1000 = 5 : 1

A. Rs. 21000
B. Rs. 17500
C. Rs. 19000
D. Rs. 24500
Let the cost prices of the colour television sold at 30% profit and 40% profit be Rs. x and Rs. (35000 – x) respectively.
Total selling price of televisions = x + 30/100 x + (35000 – x) + 40/100 (35000 – x)
=> 130/100 x + 140/100 (35000 – x) = 35000 + 32/100 (35000)
x = 28000
35000 – x = 7000
Difference in the cost prices of televisions = Rs. 21000

A. 21
B. 22
C. 23
D. 24
Let the initial number of members in the group be n.
Initial total weight of all the members in the group = n(48)
From the data,
48n + 78 + 93 = 51(n + 2) => 51n – 48n = 69 => n = 23
Therefore there were 23 members in the group initially.