Question

Clue #1: The sum of the digits of a 3 digit number is 20. Clue #2: The tens digit is 2 less than the hundreds digit. Clue #3: The units digit is 12 less than the sum of the other two digits What is the 3 digit number, show or explain how you solved the problem. Help me! Please show work

Answer 1

Answer: The number is 974

Step-by-step explanation:

First, any 3 digit number can be written as:

N = a*100 + b*10 + c

Where a, b, and c are single-digit numbers.

a is the hundreds digit

b is the tens digit

c is the unit digit

We can write the clues as:

#1: a + b + c = 20

#2: b = a - 2

#3: c = a + b - 12

Then we have a system of equations:

a + b + c = 20

b = a - 2

c = a + b - 12

To solve this, we need to isolate one of the variables in one equation and then replace this in the other equations, we can see that b is already isolated in the second equation, then we can replace that in the first and third equations:

a + (a - 2) + c = 20

c = a + (a - 2) - 12

Now we can see that c is isolated in the second equation, then we can replace that in the first one to get:

a + (a - 2) + (a + (a - 2) - 12) = 20

Now we can solve this for a:

a + a - 2 + a + a -2 - 12 = 20

4*a - 16 = 20

4*a = 20 + 16

4*a = 36

a = 36/4 = 9

With this, we can find the values of b and c.

b = a - 2 = 9 - 2 = 7

c = a + b - 12 = 9 + 7 - 12 = 4

Then the 3-digit number is:

N = a*100 + b*10 + c = 9*100 + 7*10 + 4 = 974

N = 974