Some plz help ?? :(

The last time i bought this product , it cost $20.00 but it looks like it cost 29. 60 today? what is the increase

Helll ! 1,400 tons of wheat of two different varieties was delivered to the silo. when processing one variety, there was 2% of waste and 3% during the processing of the second variety of wheat. after the processing, the amount of remaining wheat was 1,364 tons. how many tons of each variety of wheat was delivered to the silo?

Which graph has a rate of change of zero