Using proportions, it is found that 21/10 divided by 2 and 4/5 represents the number of shifts that Jammar worked.
<h3>What is a proportion?</h3>
A proportion is a fraction of a total amount, and the measures are related using a rule of three. Due to this, relations between variables, either direct or inverse proportional, can be built to find the desired measures in the problem.
For this problem, we have that following<em> rule of three</em>:
One shift - 2 and 4/5 hours.
x shifts - 21/10 hours.
Applying cross multiplication, the number of shifts is found as follows:
2 4/5x = 21/10.
x = (21/10)/(2 4/5)
Hence 21/10 divided by 2 and 4/5 represents the number of shifts that Jammar worked.
More can be learned about proportions at brainly.com/question/14398287
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