A person paid Rs. 17000 for a motor-car after a single discount of 15%. If he is given successive discount of 5% and 10% then how much he would pay ?

Answer: Option C

Cost price of motor-car = Rs. 17000
Mark price of motor-car
$$\begin{array}{rl}& =\text{Rs}\text{. 17000}\times \frac{100}{85}\\ & =\text{Rs}\text{. 20000}\end{array}$$
After successive discount,Cost price
$$\begin{array}{rl}& =\text{Rs}\text{. 20000}\times \frac{95}{100}\times \frac{90}{100}\\ & =\text{Rs}\text{. 17100 }\end{array}$$