2
Q:

123 typists typeed 984 papers in 1/15 hour. The number of papers typed for  minute by a average typist is:

A) 1 B) 2
C) 3 D) 5

Answer:   B) 2



Explanation:

Use unitary method:

In \inline \frac{1}{15} hours, 123 typists can type 984 paper

In 1 minute, 123 typists can type  \inline \frac{984}{4} = 246 papers

In 1 minute, 1 typist can type \inline \frac{246}{123} =2 papers      [ Hint \inline \frac{1}{15} hours = 4 minutes]

Q:

It costs Rs. p each to send the first thousand messsages and Rs. q to send each subsequent one . If r is greater than 1,000, how many Rupees will it cost to send r messages ?

A) 1000 (r - p) + pq B) 1000 p + qr
C) 1000 (r - q) + pr D) 1000(p - q) + qr
 
Answer & Explanation Answer: D) 1000(p - q) + qr

Explanation:

We need to find the total cost to send r messsages, r > 1000.

The first 1000 messsages will cost Rs.p each (Or) 

The total cost of first 1000 messsages = Rs.1000p

The remaining (r - 1000) messsages will cost Rs.q each (Or)

The cost of the (r - 1000) = Rs.(r - 1000)y

 

Therefore, total cost = 1000p + rq - 1000q

= 1000(p - q) + qr

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4 58
Q:

Sriram was conducting an experiment in which the average of 11 observations came to be 92, while the average of first five observations was 89, and that of the last five was 86. What was the measure of the 6th observation ? 

A) 134 B) 137
C) 139 D) 141
 
Answer & Explanation Answer: B) 137

Explanation:
This can be done as,
 
(11 × 92)  -  (5 × 89)  -  (5 × 86) 
 
= 1012- 445 - 430 = 137
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7 89
Q:

In a mens hostel, there were 95 students. To accommodate 30 more students the average is decreased by rupees 5. But total expenditure increased by Rs.500. Find the total expenditure of the hostel now ?

A) Rs. 4680 B) Rs. 4420
C) Rs. 4960 D) Rs. 5480
 
Answer & Explanation Answer: A) Rs. 4680

Explanation:

Let the expenditure on the 95 students be 'x'

Then,

95x + 500 = 120(x – 5)
95x + 500 = 120x - 600
120x - 95x = 1100
25x = 1100
=> x = 44

Therefore, total expenditure of the hostel becomes
95 x 44 + 500 = 4680.

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11 321
Q:

There are 100 students in 3 sections A, B and C of a class. The average marks of all the three sections was 84. The average of B and C was 87.5 and the average marks of students in A section was :

A) 20 B) 35
C) 54 D) 40
 
Answer & Explanation Answer: A) 20

Explanation:

Numbers of students in section A = x
∴ Numbers of students in section B and C = (100 – x)
∴ x 70 + (100 – x) 87.5 = 84 100
=> 70x + 87.5 100 – 87.5x = 8400
=> 8750 – 17.5x = 8400
=> 17.5x = 8750 – 8400 => x = 20.

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14 578
Q:

The average monthly salary of 24 employees in an organisation is Rs. 1500. If the manager's salary is added, then the average salary increases by Rs. 400. What is the manager's monthly salary ?

A) Rs. 8840 B) Rs. 11,500
C) Rs. 12,800 D) Rs. 9450
 
Answer & Explanation Answer: B) Rs. 11,500

Explanation:

Manager's monthly salary

= Rs. (1900 x 25 - 1500 x 24) = Rs. 11,500

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5 360