An animal shelter spends $3.00 per day to care for each bird and $7.00 per day to care for each cat. Skylar noticed that the shelter spent $111.00 caring for birds and cats on Wednesday. Skylar found a record showing that there were a total of 21 birds and cats on Wednesday. How many birds were at the shelter on Wednesday?

Anyone know? is appreciated! will mark brainliest if correct!

Amanager recorded the number of bicycles sold by his company each quarter. his projected sales after t years is given by the expression below. which of the following statements best describes the expression? a. the initial sales of 575 bicycles increases at the rate of 4% over 4 quarters. b. the initial sales of 575 bicycles increases at the rate of 18% over 4 years. c. the initial sales of 575 bicycles increases at the rate of 4% over t quarters. d. the initial sales of 575 bicycles increases at the rate of 18% over t years.

The american academy of pediatrics wants to conduct a survey of recently graduated family practitioners to assess why they did not choose pediatrics for their specialization. provide a definition of the population, suggest a sampling frame, and indicate the appropriate sampling unit.