Chose all the properties that were used to simplify the following problem

Two blends of tea are mixed to make a blend that will be sold at the fair. black tea sells for $2.20 per pound and orange pekoe tea sells for $3.00 per pound. how much of each should be used to obtain a 4lb blend selling for $2.50 per pound?

The curved part of the figure is the semicircle what is the best approximation for the area of this figure

Samuel deposited money in an account that’s pays an annual simple interest rate at 3.5%. at the end of 5 years, samuel earns $2625.00 in interest. how much money did he deposit in the account?