Question

How many three digit natural numbers are divisible by $4$?

Answer 1

$\begin{array}{c}Thethreedigitalnumberwhichisdivisibleby4is\\ 100,104,108,..........996\\ firstterm=100\\ d=104-100=4\\ lastterm=996\\ Then,\\ Tn=a=(n-1)\times 4\\ 996=100+(n-1)\times 4\\ 996-100=(n-1)4\\ \frac{896}{4}=(n-1)\\ 224=(n-1)\\ \therefore n=225\\ 225threedigitsnumberwhichisdivisibleby4\end{array}$