askvity

What is a certain two digit number is four times the sum of its digits?

Published in Number Puzzles 2 mins read

The two-digit number that is four times the sum of its digits is 24.

Finding the Number

Let's break down how to find this number:

  • Let the two-digit number be represented as 10a + b, where a is the tens digit and b is the units digit.

  • According to the question, the number is four times the sum of its digits. This can be written as:

    10a + b = 4(a + b)

  • Simplifying the equation:

    10a + b = 4a + 4b
    6a = 3b
    2a = b

  • This tells us that the units digit (b) is twice the tens digit (a). We can test values for a to find possible two-digit numbers:

    • If a = 1, then b = 2, and the number is 12.
    • If a = 2, then b = 4, and the number is 24.
    • If a = 3, then b = 6, and the number is 36.
    • If a = 4, then b = 8, and the number is 48.

    We need to check which of these numbers satisfy the original condition that the number is four times the sum of its digits.

  • Check each possible number:

    • 12: 1 + 2 = 3. 4 * 3 = 12 (Correct)
    • 24: 2 + 4 = 6. 4 * 6 = 24 (Correct)
    • 36: 3 + 6 = 9. 4 * 9 = 36 (Correct)
    • 48: 4 + 8 = 12. 4 * 12 = 48 (Correct)

Based on the provided reference: "Hence the required numbers = 10(2)+4=20+4=24. A two digit number is four times the sum of the digits. It is also equal to 3 times the product of digits."

Therefore, one such number is 24.

Related Articles