Can someone explain to me how to do this? My teacher just threw this at us instead of teaching it to us-

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 value of y will make the inequality y< -1 false?

The average length of a king cobra is 3.7 m. the record length is 1.88 m longer than the average. how long is the record holder?