Question

The difference of the sum of even numbers and sum of odd numbers between 10 and 20 is:
(a) 13
(b) 14
(c) 15
(d) 16

Answer 1

Hint: First of all find the even and odd numbers lying between 10 and 20. Even numbers between 10 and 20 are 12, 14, 16, 18 and odd numbers between 10 and 20 are 11, 13, 15, 17, 19. Now, add the even numbers and odd numbers separately and then take the difference between the sum of even numbers and odd numbers.

Complete step-by-step answer:
The even numbers lying between 10 and 20 are:
12, 14, 16, 18
The odd numbers lying between 10 and 20 are:
11, 13, 15, 17, 19
Now, we are going to add the even numbers lying between 10 and 20.
$\begin{align}
  & 12+14+16+18 \\
 & =60 \\
\end{align}$
We are also going to add the odd numbers lying between 10 and 20.
$\begin{align}
  & 11+13+15+17+19 \\
 & =75 \\
\end{align}$
We are asked in the problem to find the difference between the sum of even and the sum of odd numbers lying between 10 and 20 so we are subtracting 60 from 75 we get,
$\begin{align}
  & 75-60 \\
 & =15 \\
\end{align}$
From the above solution, the difference of the sum of even numbers and sum of odd numbers between 10 and 20 is 15.

So, the correct answer is “Option C”.

Note: The blunder that could happen is you might have counted in the even numbers as 10 and 20 also. Be careful while writing the even and odd numbers because the problem is saying we have to find the sum of even and odd numbers lying between 10 and 20 not from 10 and 20. In writing the odd numbers you won’t experience such a problem because 10 and 20 is even but in writing even numbers it will cost you.