Question

The variable c varies directly with a and inversely with b, and c=3\20 when a =2 and b=5

Answer 1

k = 3/8

when a=1 and b=5, c=3/40

Answer 2

The required equation will be expressed as c = 3a/8b

How to solve variation

If the variable c varies directly with a and inversely with b, this is expressed as:

c = ka/b

Given the folloiwng parameter

c = 3/20

a  = 2

b = 5

3/20 = 2k/5

40k = 15

k = 15/40

k = 3/8

The required equation will be expressed as c = 3a/8b

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