Number System Questions for Competitive Exams
A rational number between $${3\over4} $$ and $${3\over8} $$ is :
(A) $${5\over9}$$
(B) $$1{9\over16}$$
(C) $${7\over9}$$
(D) $${7\over3}$$
Correct Answer : A
In a school $${1\over10} $$ of the boys are same in number as $${1\over4}$$ of the girls and $${5\over8} $$ of the girls are same in number as $${1\over4}$$ of the boys. The ratio of the boys to girls in that school is:
(A) 4 : 3
(B) 3 : 2
(C) 2 : 1
(D) 5 : 2
Correct Answer : D
If * means adding 6 times the second number to the first number then ( 1 * 2 ) * 3 equals :
(A) 121
(B) 91
(C) 31
(D) 93
Correct Answer : C
How many even three-digit numbers can be formed from the digits 1 , 2 , 5 , 6 and 9 without repeating any of the digits?
(A) 40
(B) 24
(C) 120
(D) 48
Correct Answer : B
What is the sum of two consecutive even numbers, the difference of whose square is 84?
(A) 42
(B) 46
(C) 38
(D) 34
Correct Answer : A
A man spends $${1\over 3}$$ of his income on food, $${2\over 5}$$ of his income house rent and $${1\over 5}$$ of his income on clothes. If he still has Rs. 400 left with him, his income is:
(A) Rs. 6000
(B) Rs. 7000
(C) Rs. 4000
(D) Rs. 5000
Correct Answer : A
How many natural numbers divisible by 7 are there between 3 and 200?
(A) 28
(B) 29
(C) 27
(D) 36
Correct Answer : A
Explanation :
Number just greater than 3 which is divisible by 7 = 7
Number just smaller than 200 which is divisible by 7 = 196
Here, a = 7, an = 196,
d = 7, n = 8
an = a + (n –1)d
⇒196 = 7 + (n – 1) × 7
⇒ 
⇒ n = 27 + 1 = 28
Note : We can find the answer after dividing 200 by 7. The quotient is our answer.
A number when divided by 296 gives a remainder 75. When the same number is divided by 37 the remainder will be:
(A) 8
(B) 1
(C) 2
(D) 11
Correct Answer : B
Explanation :
Let number (dividend) be X.
∴ X = 296 × Q + 75 where Q is the quotient and can have the values 1, 2, 3 etc.
= 37 × 8 × Q + 37 × 2 + 1
= 37 (8Q + 2) + 1
Thus we see that the remainder is 1.
[Remark : When the second divisor is a factor of the first divisor, the second remainder is obtained by dividing the first remainder by the second divisor.
Hence, divide 75 by 37, the remainder is 1].
Which of the following is the largest fraction $${6\over7},{5\over6},{7\over8},{4\over5} ?$$
(A) $${6\over7}$$
(B) $${5\over6}$$
(C) $${7\over8}$$
(D) $${4\over5}$$
Correct Answer : C
Two number 11284 and 7655, when divided by a certain number of three digits, leaves the same remainder. The sum of digits of such a three - digits number is:
(A) 25
(B) 250
(C) 125
(D) 225
Correct Answer : C
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Vikram Singh
Providing knowledgable questions of Reasoning and Aptitude for the competitive exams.
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