Does every number have a reciprocal

Maria donates a fixed amount, a, to a charity each month. if she donates $300 in 12 months, what is the equation for a? a. a + 300 = 12 b. a × 300 = 12 c. a × 12 = 300 d. a + 12 = 300 e. a + 32 = 100

$5400 is? invested, part of it at 11? % and part of it at 8? %. for a certain? year, the total yield is ? $522.00. how much was invested at each? rate?

The area of each triangle is 7 square units. the surface area of the triangular prism is