What is the domain for a continuous function

Astore sells two types of radios. one type sells $87 and the other for $119. if 25 were sold and the sales were $2495, how many of the $87 radios were sold a) 5 b) 20 c) 15 d)10

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

Triangle knm is what is true about the sides of knm