Numbers Questions Answers

• 8. What is the largest 4 digit number exactly divisible by 88

  1. 9900
  2. 9999
  3. 9988
  4. 9944

  Answer :

  Option D

  Explanation:

  Largest 4 digit number is 9999
  After doing 9999 ÷ 88 we get remainder 55
  Hence largest 4 digit number exactly divisible by 88 = 9999 - 55 = 9944

• 9. 217 * 217 + 183 * 183

  1. 70578
  2. 82578
  3. 80578
  4. 80568

  Answer :

  Option C

  Explanation:

  \begin{aligned}
  \frac {1}{2}\times 2(a^2 + b^2) = \frac {1}{2} \times [(a + b)^2 + (a - b)^2]
  \end{aligned}
  \begin{aligned}
  = \frac {1}{2} \times [(217 + 183)^2 + (217 - 183)^2] = 80578
  \end{aligned}

• 10. 469157 * 9999

  1. 1691100843
  2. 4591100843
  3. 4691100843
  4. 3691100843

  Answer :

  Option C

  Explanation:

  469157 * (10000 - 1)
  = 4691570000 - 469157
  = 4691100843

• 11. 1307 * 1307 = ?

  1. 1608249
  2. 1508249
  3. 1408249
  4. 1708249

  Answer :

  Option D

  Explanation:

  \begin{aligned}
  (a + b)^{2} = (a^2 + b^2 + 2ab)
  \end{aligned}
  \begin{aligned}
  1307^{2} = (1300 + 7)^2 = (1690000 + 49 + 18200)
  \end{aligned}

• 12. There are four prime numbers written in ascending order. The product of first three is 385 and that of last three is 1001. The last number is:

  1. 9
  2. 13
  3. 15
  4. 12

  Answer :

  Option B

  Explanation:

  \begin{aligned} \frac{abc}{bcd} = \frac{385}{1001}
  => \frac{a}{d} = \frac{5}{13} \end{aligned}
  So d = 13

• 13. 7589 - X = 3434

  1. 4155
  2. 2321
  3. 3155
  4. None of above

  Answer :

  Option A

• 14. Simplify 586645 * 9999

  1. 5865863355
  2. 5665863355
  3. 4865863355
  4. 4665863355

  Answer :

  Option A

  Explanation:

  Although it is a simple question, but the trick is to save time in solving this.
  Rather than multiplying it we can do as follows:
  586645 * (10000 - 1) = 5866450000 - 586645 = 5865863355