0
Q:

If a positive integer n, divided by 5 has a remainder 2, which of the following must be true?

A) n is odd B) n + 1 cannot be a prime number
C) (n + 2) divided by 7 has remainder 2 D) n + 3 is divisible by 5

Answer:   D) n + 3 is divisible by 5



Explanation:

You can find the integers which when divided by 5 have a remainder 2 by adding 2 to all multiples of 5. So we have n = 7 , 12, 17, 22 etc.

From this series we can see that n does not have to be odd.

Also n + 1 can be a prime because, for example, 12 + 1 = 13

And (n + 2) / 7 has a remainder 2 in some cases but not all.

Remember the question asks us for what MUST be true, and we see that none of the statements are true in all cases. However, adding 3 to any of the values of n will always give a multiple of 5.

Q:

Which expression is equivalent to i233?

A) i B) 1
C) -i D) -1
 
Answer & Explanation Answer: A) i

Explanation:

We know that,

i2 = -1i3 = i2 x i = -1 x i = -ii4 = i2 x i2 = -1 x -1 = 1Hence, i233  =i4 x 58 + 1 = i232 x i1 = 1 x i = i

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0 54
Q:

The product of a number and its multiplicative inverse is

A) 1 B) 0
C) -1 D) Infinity
 
Answer & Explanation Answer: A) 1

Explanation:

The mutiplicative inverse of a number is nothing but a reciprocal of a number.

Now, the product of a number and its multiplicative inverse is always equal to 1.

 

For example :

Let the number be 15

Multiplicative inverse of 15 = 1/15

The product of a number and its multiplicative inverse is = 15 x 1/15 = 1.

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0 81
Q:

25 divided by 7

A) 3.571 B) 35.71
C) 0.351 D) 0.0357
 
Answer & Explanation Answer: A) 3.571

Explanation:

Here we have 25 divided by 7.

25 will not go directly in 7

Hence, we get the result in decimals.

25/7 = 3.571.

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1 100
Q:

Which of the following is not a prime number?

A) 5 B) 11
C) 21 D) 37
 
Answer & Explanation Answer: C) 21

Explanation:

A prime number is a whole number greater than 1 whose only factors are 1 and itself.

 

Factors of 5 are 1, 5

Factors of 11 are 1, 11

Factors of 21 are 1, 3, 7, 21

Factors of 37 are 1, 37.

 

Hence, according to the definition of a prime number, 21 is not a prime number as it has more than two factors.

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1 89
Q:

What are the Multiples of 4?

Answer

The Multiples of 4 are 4, 8, 12, 16, 20, 24, 28, 32, 36, 40 upto 40. Mutiples of 4 means which can be divided by 4 leaving remainder '0'.


Common Multiples of 4 & 6 are 12, 24, 36, 48, 60 upto 60.

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5 604
Q:

The sum of three consecutive odd numbers is 93. What is the middle number?

A) 31 B) 33
C) 29 D) 27
 
Answer & Explanation Answer: A) 31

Explanation:

Let the three consecutive odd numbers be x, x+2, x+4

Then,

x + x + 2 + x + 4 = 93

=> 3x + 6 = 93

=> 3x = 87

=> x = 29 => 29, 31, 33 are three consecutive odd numbers.

 

Therefore, the middle number is 31.

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7 1225
Q:

How many numbers up to 300 and 700 are divisible by 2, 3 and 7 both together ?

A) 7 B) 9
C) 11 D) 5
 
Answer & Explanation Answer: B) 9

Explanation:

LCM of 2, 3, 7 is 42.

=> (700 – 300)/42 = 9  22/42 => 9 Numbers.

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15 2679
Q:

In a triangle ABC, angle 'a' is the smallest one & A+7B = 112. Find the range of value 'c' ?

A) 138 to 164 B) 125 to 147
C) 148 to 158 D) 152 to 164
 
Answer & Explanation Answer: D) 152 to 164

Explanation:

A+7B=112

it is clear that A = 14, then it becomes A>=B, but A is smallest angle) given
so, range of A is 0.0001 to 13.9999 ( I am taking upto 4 decimal places)
so, range of B becomes 14 to 16 ( after rounding off to 4 decimal places)
so, range of C becomes 152 to 164 ( after rounding off to 4 decimal places)

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6 2607