Convex lens has a diameter of 30mm and a depth of 5mm at the center. How far from the vertex is the focus.

The bike store marks up the wholesale cost of all the bikes they sell by 30% and andre wants to buy a bike that has a price tag of 125 what was the wholesale cost of the bike

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?