Answer: The 3rd number in the sequence is 29.
Step-by-step explanation: What we have is a sequence of “ODD” numbers and they are consecutive, which means they come one after another with regular intervals. We don’t have any of the numbers but we can start by saying ‘let x represent the first number in the sequence’
With this in mind, we can now assume all other four numbers in the sequence. Therefore if the 1st number is x, the 2nd number would be x + 2, and the the 3rd number would be x + 4, 4th number would be x + 6 while the 5th number would be x + 8.
The reason is that, every odd number is an addition of two to the previous odd number. For instance, if you start with 3, the next odd number would be 3+2 (5), and so on.
Therefore we can now write our consecutive odd numbers as follows;
x + (x + 2) + (x + 4) + (x + 6) + (x + 8)
Remember that all the numbers add up to 145. Therefore,
x + x + 2 + x +4 + x + 6 + x + 8 = 145
5x + 20 = 145
Subtract 20 from both sides of the equation
5x = 125
Divide both sides of the equation by 5
x = 25.
The first odd number is 25, which means the 3rd odd number is 25 + 4.
Therefore the 3rd odd number is 29.
= 18 unit²