76
Q:

If you write down all the numbers from 1 to 100, then how many times do you write 3 ?

A) 11 B) 18
C) 20 D) 21

Answer:   C) 20



Explanation:

Clearly, From 1 to 100, there are ten numbers with 3 as the unit's digit - 3, 13, 23, 33, 43, 53, 63, 73, 83, 93 and ten numbers with 3 as the ten's digit - 30, 31, 32, 33, 34, 35, 36, 37, 38, 39.

 

So, required number = 10 + 10 = 20.

Q:

Find the least number by which 175760 be divided to make it a perfect cube.

A) 6 B) 10
C) 9 D) 30
 
Answer & Explanation Answer: B) 10

Explanation:

175760 =2³ x 2 x 5 x 13³
= 2³ x 2 x 5 x 13³

To make perfect cube, it must be divided by 2 x 5 = 10

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2 90
Q:

The sum of three consecutive multiples of 3 is 72. What is the second largest number ?

A) 27 B) 24
C) 21 D) 42
 
Answer & Explanation Answer: B) 24

Explanation:

Let the numbers be 3x, 3x + 3 and 3x + 6.
Then,
3x + (3x + 3) + (3x + 6) = 72
9x = 63
x = 7
Largest number = 3x + 6 = 27.

=> Second largest number = 27 - 3 = 24

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1 115
Q:

When 5% is lost in grinding Maize, a country has to import 20 million bags; but when only 2% is lost, it has to import only 15 million bags. Find the quantity of Maize, which grows in the country ?

A) 188 million B) 166 2/3 million
C) 192 3/4 million D) None
 
Answer & Explanation Answer: B) 166 2/3 million

Explanation:

5% - 2% = 3%
=> 3% ------ 5 million bags
100% ---- ?
=> 166 2/3 million bags.

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2 152
Q:

If x = √8 - √7, y = √6 - √5 and z = √10 - 3, which of the following is true  ?

A) x > y < z B) x < y < z
C) x > y > z D) z < x < y
 
Answer & Explanation Answer: D) z < x < y

Explanation:

x = √8 - √7 = 1/(√8 + √7) and y = √6 - √5 = 1/(√6 + √5) and z = √10 - 3 = 1/(√10 + 3)

As (√8 + √7) > (√6 + √5), (√8 - √7) < (√6 - √5)

As (√10 + 3) > (√8 + √7) > (√6 + √5)

z < x < y.

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1 124
Q:

Difference between two numbers is 5, six times of the smaller lacks by 6 from the four times of the greater. Find the numbers ?

A) 12 & 7 B) 13 & 8
C) 15 & 10 D) 14 & 9
 
Answer & Explanation Answer: A) 12 & 7

Explanation:

x – y = 5

4x – 6y = 6

x = 12 y = 7

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2 152