When finding the area of a circle if you are given the diameter how will you solve to find the radius

Sheila wants to bake six muffins but the recipe is for 12 muffins . this means you only need half of the ingredients listed how much of the of each ingredient does she need? one cup and banana chips ,7 tablespoons oil , two eggs, 3/4 cups flour 1/4 cup walnuts show all you work and justify your answer using a baby toulmin.

The population in a city is modeled by the equation p(d)= 100,000*(1+0.3) where d is the number of decades since 1970

The sum of two consecutive mile markers on the interstate is 417417. find the numbers on the markers