3
Q:

The average of a set of whole numbers is 27.2. when the 20% of the elements are eliminated from the set of numbers then the average become 34. The number of elements in the new set of numbers can be :

A) 27 B) 35
C) 52 D) 63

Answer:   C) 52



Explanation:

only (c) is correct since it is divisible by 4.

Let the original number of element  be x then the new no.of elements wil be 

                                                \inline \frac{4x}{5}=K

So K must be divisible by 4

Since,      x =  \inline \frac{K \times 5}{4} 

Q:

If price of rice increased by 25%, so that a man is can able to purchase 5 kg less rice in Rs. 500. Find the original price of rice per kg ?

A) Rs. 20 B) Rs. 24
C) Rs. 26 D) Rs. 29
 
Answer & Explanation Answer: A) Rs. 20

Explanation:

Let the original price of rice be Rs. x

Let rice a man can buy for Rs. 500 at rs. x/kg be = R kgs

From given data, for Rs. 500

x ---- R kgs

(x + 25x/100) ---- (R - 5) kgs

=> Rx = (R - 5)(x + 25x/100)

=> Rx = (R - 5)(125x/100)

=> 100Rx = 125Rx - 625x

=> R = 25

So at rate of Rs. x/kg, man get 25 kgs for Rs. 500

=> x = 500/25 = Rs. 20

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7 275
Q:

A earns 50% of B's salary, B earns 80% of C's salary. If the total earnings for a month is Rs. 22000, then what is the earning for A ?

A) Rs. 4000 B) Rs. 4200
C) Rs. 4400 D) Rs. 4600
 
Answer & Explanation Answer: A) Rs. 4000

Explanation:

Let C's salary be Rs. x

Then B's salary = 80x/100

=> A's salary = (50/100) * (80x/100) = 40x/100

But given total earnings in a month = 22000

=> x + 80x/100 + 40x/100 = 22000

=> x + 120x/100 = 22000

=> x = 10000

=> A's salary = 40 x 10000/100 = Rs. 4000 

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3 153
Q:

A man reads 3/7 of a book on a day and 2/5 of the remaining, on the second day. If the number of pages still unread are 36, how many pages did the book contain ?

A) 105 B) 101
C) 98 D) 109
 
Answer & Explanation Answer: A) 105

Explanation:

Let number of pages in a book = p

According to questions

p - [3p/7 + (2/5 x 4p/7)] = 36

= p - 23p/35 = 36

=> 12p = 36 × 35

p = 105

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6 240
Q:

At an examination in which maximum marks are 500. P got 10% less than Q, Q got 25% more than R and R got 20% less than S. If P got 360 marks what percentage of marks was obtained by S ?

A) 77 B) 74
C) 80 D) 83
 
Answer & Explanation Answer: C) 80

Explanation:

Let marks obtained by S = M

R's marks = 0.80M

Q's marks = 1.25 (0.80M)

P's marks = (0.90) (1.25) (0.80M)

= 0.9M

But 0.9M = 360

M = ?

M = 400

Hence % of marks obtained by S

= 400/500 x 100 = 80%.

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4 252
Q:

One-third of the boys and one-half of the girls of a college participated in a sport. If the number of participating students is 300, out of which 100 are boys. What is the total number of students in the college ?

A) 550 B) 575
C) 625 D) 700
 
Answer & Explanation Answer: D) 700

Explanation:

Let number of boys = B

Number of girls = G

From the given data,

1B/3 + 1G/2 = 300

But given B/3 = 100

=> B = 300

G/2 = 300 - 100

G = 200 x 2

=> G = 400

Therefore, total number of students in the college = B + G = 700.

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7 200