9. Arun bought a pair of skates at a sale where the discount is given was 20%. If the amount he pays is ₹ 1,600, find the marked price.
so,if SP is ₹ 1 then marked price = ₹ $$\frac { 100 }{ 80 }$$
Similarly, if SP is ₹ 1,600 then marked price = ₹ $$\frac { 100 }{ 80 } \times 1600 = ₹ 2,000$$