Abag holds 1 blue block and 3 yellow blocks how many green blocks should be added to the bag to make the probability of randomly selecting a green block from the bag equal to half

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?

Which of the following is the shape of a cross section of the figure shown below

Tan198=asin164=? how to solve this? ?