An article Is marked at Rs.5,000. The shopkeeper allows successive discounts of x%,y%, z% on it. The net selling price is
1). Rs. $\frac{(100 -x)(100 +y)(100 +z)}{200}$ %
2). Rs. $\frac{(100 +x)(100 +y)(100 -z)}{200}$ %
3). Rs. $\frac{(100 -x)(100 -y)(100 -z)}{200}$%
4). Rs. $\frac{(100 -x)(100 +y)(100 -z)}{200}$%