One number is 3 times a first number, a third number is 100 more than the first number. if the sum of the three number is 245. find the numbers

The numbers are 29, 87 and 129.

To find these, you have to first assume that the first number is equal to x. After that we can write statements for the other numbers based on that. The second number is three times the first, which makes it 3x. The third is 100 more than the first, which makes it x + 100. Now we can add these 3 together and set equal to 245 to solve.

x + 3x + x + 100 = 245 > Combine like terms

5x + 100 = 245 > Subtract 100 from both sides

5x = 145 > Divide both sides by 5

x = 29

You can then plug the 29 into each of the other equations to find the remaining numbers.

3x = 87

x + 100 = 129