Arithmetic Mcqs

The average of the two-digit numbers, which remain the same when the digits interchange their positions, is__________?

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The average of the two-digit numbers, which remain the same when the digits interchange their positions, is__________?

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 total of 3000 chocolates were distributed among 120 boys and girls such that each boy received 2 chocolates and each girl received 3 chocolates. Find the respective number of boys and girls?

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A total of 3000 chocolates were distributed among 120 boys and girls such that each boy received 2 chocolates and each girl received 3 chocolates. Find the respective number of boys and girls?

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

Rs. 6000 is lent out in two parts. One part is lent at 7% p.a simple interest and the other is lent at 10% p.a simple interest. The total interest at the end of one year was Rs. 450. Find the ratio of the amounts lent at the lower rate and higher rate of interest?

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Rs. 6000 is lent out in two parts. One part is lent at 7% p.a simple interest and the other is lent at 10% p.a simple interest. The total interest at the end of one year was Rs. 450. Find the ratio of the amounts lent at the lower rate and higher rate of interest?

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 trader purchased two colour televisions for a total of Rs. 35000. He sold one colour television at 30% profit and the other 40% profit. Find the difference in the cost prices of the two televisions if he made an overall profit of 32%?

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A trader purchased two colour televisions for a total of Rs. 35000. He sold one colour television at 30% profit and the other 40% profit. Find the difference in the cost prices of the two televisions if he made an overall profit of 32%?

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

The average weight of a group of persons increased from 48 kg to 51 kg, when two persons weighing 78 kg and 93 kg join the group. Find the initial number of members in the group?

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The average weight of a group of persons increased from 48 kg to 51 kg, when two persons weighing 78 kg and 93 kg join the group. Find the initial number of members in the group?

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.