Ticket for an adult is Rs 500 and a child is Rs 200. 1 child goes free with two adults. If a group has 20 adults and 8 children what will be the discount the group get?

Cost price of adult ticket = Rs. 500 and child ticket = Rs. 200

For 20 adults and 8 children, total cost = $$(20 \times 500) + (8 \times 200)$$

= Rs. (10,000 + 1,600) = Rs. 11,600

If one child goes free with two adults, => 8 children will go with 16 adults, thus all the children will go for free.

Cost of 20 adults = $$20 \times 500 = Rs. 10,000$$

Discount % = $$\frac{11600 - 10000}{11600} \times 100$$

= $$\frac{1600}{116} = 13.79 \%$$