Marked price of an item is Rs 900. On purchase of 2 items discount is 6%, on purchase of 3 items discount is 12%. Rajani buys 5 items, what is the effective discount?
The marked price of a pen is Rs 3000. The shopkeeper gives two successive discounts of 15% and a% to the customer. If the customer pays Rs 2142 for the pen, then what is the value (in percentage) of a?