Numbers Questions Answers

• 1. Which is smallest prime number

  1. 0
  2. 2
  3. 3
  4. 7

  Answer :

  Option B

• 2. A number when divided by the sum of 555 and 445 gives two times their difference as quotient and 30 as remainder. The number is

  1. 22030
  2. 220030
  3. 23030
  4. 24030

  Answer :

  Option B

  Explanation:

  (555 + 445) * 2 * 110 + 30 = 220000 + 30 = 220030

• 3. 587 * 999 = ?

  1. 586411
  2. 586413
  3. 486411
  4. 486413

  Answer :

  Option B

  Explanation:

  Trick: 587 * (1000 - 1) = 587000 - 587 = 586413

• 4. What is the unit digit in
  \begin{aligned}
  (6324)^{1797} \times (615)^{316} \times (341)^{476}
  \end{aligned}

  1. 1
  2. 5
  3. 7
  4. 0

  Answer :

  Option D

• 5. The greatest number by which the product of three consecutive multiples of 3 is always

  1. 54
  2. 81
  3. 162
  4. 243

  Answer :

  Option C

  Explanation:

  3*6*9 = 162

• 6. Which of the following is a prime number

  1. 9
  2. 2
  3. 4
  4. 8

  Answer :

  Option B

  Explanation:

  A prime number is a natural number greater than 1 which has no positive divisors other than 1 or itself.
  So from above options 2 is that number

• 7. Simplify (212 * 212 + 312 * 312 )

  1. 132288
  2. 142088
  3. 142188
  4. 142288

  Answer :

  Option D

  Explanation:

  Trick: Above equation can be solved by using following formula
  \begin{aligned}
  (a^2 + b^2) = \frac{1}{2}((a+b)^2 + (a-b)^2)
  \end{aligned}