d is inversely proportional to c

when c = 280, d = 25

Find the value of d when c = 350

please explain

d is inversely proportional to c means that d = k/c where k is a constant.

Find the value of k by using the fact that d = 25 when c = 280: 25 = k/280 so k = 25*280 → 7000

Now when c = 350 we have d = 7000/350 so d = 20

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