Question

i am a 3 digit number between 400 and 800 .my digits add upto 15. my ten's digit is twice my hundreds digit. what number am i?​

Answer 1

We have been given that the required number is $3$ digit number between $400$ and $800$. Its digits add up to $15$. Its ten's digit is twice its hundred's digit.

Since ten's digit is twice its hundred's digit, the only possible set is $4$ and $8$.

And given that the total sum is $15$.

Therefore, the one's digit is $=15-(4+8)=3$.

Hence, the required number is $483$.

Answer 2

Answer:

Number is 483

Step-by-step explanation:

Given,

The required number is 3 digit number between 400 and 800.

Sum of the digits of the number = 15

The digit in the ten's place is twice the digit in the hundred's place.

Let x,y,z are the digits in the 100th place, 10th place, and one's place respectively.

Hence from the given conditions, we have

x + y +z = 15 --------(1)

y = 2x -------- (2)

Since the required number is between 400 and 800, the only possible digit in the hundred's place satisfying the equation (2) is '4'

So x = 4

from equation (2) we get, y = 8

Substituting the above values of 'x' and 'y' in equation (1) we get,

4+8+z = 15

12 +z = 15

z = 15 -12 = 3

z =3

Hence the required number is 483