Lena jarred 10 liters of jam after 2 days. How many days does Lena need to spend making jam if she wants to jar 20 liters of jam in all? Assume the relationship is directly proportional.

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?

Pls the last one and it has to be like number 6

Events a and b are independent. the probability of a occurring is 2/5. the probability of b occurring is 1/4. what is p(a and b)?