I 1. Mr. Starr began working in his garden at
8:00 A. M. He finished working at 11:30
A. M. How long did Mr. Starr work in his
garden?
A. 2 hours 30 minutes
B. 3 hours
C. 3 hours 30 minutes
D. 4 hours

300pi

step-by-step explanation:

it has to have an angle of 90 degrees

chemists are often responsible for designing a chemical reaction and analyzing the products obtained from it. one significant part of designing a chemical reaction is determining the amount of each reactant that is needed and the amount of each product that will be produced. in order to do so, chemists use stoichiometry, the quantitative relationships between reactants and products.