Step-by-step explanation:

The answer is 210 just multiply 420 by 7 cause theres 7 days is a week you get 2,940 minus from 3,150
7a + 6c + 9a - 15c
-- Look for all the 'a's 7a, 9a
-- Addum up 16a
-- Look for all the 'c's 6c, -15c
-- Addum up -9c
-- Write the results 16a - 9c
In 20 minutes, John can wrap 10 small boxes and Hank can wrap 12 small boxes. So, Hank can wrap more small boxes in 20 minutes than John can.
Step-by-step explanation:
Given,
John wraps;
2 small boxes = 4 minutes
1 small box = 
In 20 minutes,
20 minutes = 
20 minutes = 10 small boxes
Hank wraps;
3 small boxes = 5 minutes
1 small box =
In 20 minutes = 

In 20 minutes, John can wrap 10 small boxes and Hank can wrap 12 small boxes. So, Hank can wrap more small boxes in 20 minutes than John can.
Keywords: division, multiplication
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Answer:
(a) 0.85
(b) 0.7225
Step-by-step explanation:
(a) The point estimate for the proportion of all such components that are not defective is given by the number of non-defective units in the sample divided by the sample size:

The proportion is 0.85.
(b) Assuming that the sample is large enough to accurately provide a point estimate for the whole population, this can be treated as a binomial model with probability of success (non-defective part) p = 0.85. Since both components must be non-defective for the system to work, the probability of two successes in two trials is:

An estimate of 0.7225 for the proportion of all such systems that will function properly.