Question 118561: Find three consecutive numbers whose sum is 60.
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! If the first unknown number is represented by x, then the second consecutive number must
be one greater than x (or x + 1) and the third consecutive number must be two greater than
x (or x + 2). The sum of the three consecutive numbers then becomes:
.
x + (x + 1) + (x + 2)
.
and this sum must equal 60. This makes the equation:
.
x + (x + 1) + (x + 2) = 60
.
Combine all the x terms on the left side and you have:
.
3x + 1 + 2 = 60
.
Add the 1 & 2 to get:
.
3x + 3 = 60
.
Get rid of the +3 on the left side by subtracting 3 from both sides and the result is:
.
3x = 57
.
Solve for x by dividing both sides of this equation by 3. Since 3 goes into 57 19 times,
the result is:
.
x = 19
.
And since the numbers are consecutive, the three numbers that you are looking for are:
.
19 and 20 and 21
.
If you add these three consecutive numbers, you get a total of 60, just as the problem
requires the sum to be. So the answer checks.
.
Hope this helps you to see how to set up and do the problem.
.
|
|
|
