For this case, the first thing we must do is define variables.
x: amount of time Miguel uses to complete the task.
y: amount of time Maria uses to complete the task.
We write the system of equations:
x + y = 60
y = (1/2) x
Solving the system we have:
x = 40 minutes
y = 20 minutes
Answer:
it take her to wash them by herself about:
y = 20 minutes
Answer:
8 3/5
false
Step-by-step explanation:
Answer:
Example:
A bag contains 3 black balls and 5 white balls. Paul picks a ball at random from the bag and replaces it back in the bag. He mixes the balls in the bag and then picks another ball at random from the bag.
a) Construct a probability tree of the problem.
b) Calculate the probability that Paul picks:
i) two black balls
ii) a black ball in his second draw
Solution:
tree diagram
a) Check that the probabilities in the last column add up to 1.
b) i) To find the probability of getting two black balls, first locate the B branch and then follow the second B branch. Since these are independent events we can multiply the probability of each branch.
ii) There are two outcomes where the second ball can be black.
Either (B, B) or (W, B)
From the probability tree diagram, we get:
P(second ball black)
= P(B, B) or P(W, B)
= P(B, B) + P(W, B)
