Looking at number 4, you first have to look at the information that you have:
On tuesday he practiced for 1 5/6 hrs
Monday he practiced for 7/10 hrs
He is supposed to practice for 1 1/4 hr.
You could write questions like:
How much more did Marco practice on Tuesday than he is supposed to practice?
This works because it does indeed involve subtraction, you would be subtracting the amount that he should have practiced from the amount of time that he did practice.
If I didn't answer the question, please message me and I will clarify!

6 0

2 years ago

Probability people where you at? 《brainlist if correct》

motikmotik

<h3>Answer: 5/9</h3>

As an approximate decimal, this is 0.5556 which converts to 55.56%

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Explanation:

Let's say there are 100 households (just for the sake of simplicity). We are told that 90% of them have answering machines. So that means 90 households have answering machines. In addition, 50 households have answering machines and call waiting. Those 50 households are part of the 90 mentioned previously.

We then select a house at random. Someone tells us (or we have some kind of prior knowledge) that whichever house is selected, they have an answering machine. We can ignore the 10 households that don't have an answering machine. Out of those 90 households, 50 have both features. So 50/90 = 5/9 is the probability of getting a household with both features.

The answer would be 1/2 or 50% if we didn't have the prior knowledge of the household having an answering machine. But with this prior knowledge, the conditions change and so does the probability.

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You could also compute 0.50/0.90 to get the same answer.

3 0

2 years ago