Tarun bought a T.V. with 20% discount on the labelled price had he bought it with 25% discount he would have saved Rs. 500. At what price did he buy the T.V.?

Let S.P. of T.V. (by trader) = Rs. 100
If S.P. is Rs. 80, then M.P. = Rs. 100
If S.P. is Rs. 100, M.P. = Rs. (100 / 80) x 100 = Rs. 125
Now, if discount is 25% then, S.P. = (75% of Rs. 125) = Rs. 375/4
Difference between two S.P. = Rs. (100 - 375/4) = Rs. 25 / 4
If difference is Rs. 25/4, S.P. = Rs. 100
If difference is Rs. 500, S.P. = Rs.(100 x 4 ) / (25 x 500) = Rs. 8000