Haryana Police Constable Model Paper 5

Given:
The numbers are even and lie between 0 and 51
Formula used;
Numbers of terms in $\mathrm{AP}$ $\left(\mathrm{n}\right)=\frac{\left(\mathrm{l}-\mathrm{a}\right)}{\mathrm{d}}+1$
Sum of $\mathrm{AP}=\left(\frac{\mathrm{n}}{2}\right)\times \left(\mathrm{a}+\mathrm{l}\right)$
Here a is first term, l is last term, d is common difference
Calculation:
The numbers are $2,4,6,.....50$
Total even numbers are $\left[\frac{\left(50-2\right)}{2}+1\right]=25$
Sum of terms = $\left(\frac{25}{2}\right)\times \left(2+50\right)=25\times 26$
⇒ Sum of terms = $650$
∴ 650 is the correct answer.