Navigate

Question Detail

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:

  • 9
  • 13
  • 15
  • 12

Answer: Option B

Explanation:

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

Similar Questions :

1. 587 * 999 = ?

  • 586411
  • 586413
  • 486411
  • 486413

Answer: Option B

Explanation:

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

2. Simplify 586645 * 9999

  • 5865863355
  • 5665863355
  • 4865863355
  • 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

3. For the integer n, if n*n*n is odd, then what is true

  • n is odd and n*n is even
  • n*n is odd
  • n is even
  • n*n is odd

Answer: Option A

4. 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

  • 22030
  • 220030
  • 23030
  • 24030

Answer: Option B

Explanation:

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

5. Find the unit digit in \begin{aligned}
(544)^{102} + (544)^{103}
\end{aligned}

  • 2
  • 4
  • 0
  • 1

Answer: Option C

Explanation:

Required digit is = \begin{aligned}
(4)^{102} + (4)^{103} \end{aligned}
as \begin{aligned} (4)^2 \end{aligned} gives unit digit 6 so \begin{aligned} (4)^{102} \end{aligned} unit digit is 6 and \begin{aligned} (4)^{103} \end{aligned} unit digit is, unit digit of \begin{aligned} 6 \times 4 \end{aligned}= 4, so answer will be unit digit of 6 + 4 = 0

Read more from - Numbers Questions Answers