Given:
The original price, CP=$65.
The initial discount on sale, D1=10%.
The additional discount, D2=15%.
If the cost price(CP) of an item is given, then the selling price after the first discount is applied is,

The additional discount is applied to the price after the first discount is applied. So, the final price after applying the second discount is,

Applying the first discount on the original price, the selling price is,

Applying the second discount on the selling price, the final selling price is,

Therefore, the final price is $49.73.
Note:
The direct formula for the final price if two successive discounts D1 and D2 are applied to a cost price CP is,
