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Question
If x varies inversely as y and y = 60 when x = 1.5. Find x. when y = 4.5.
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Solution
If x varies inversely as y.
∴ xy = k (constant) ...(i)
If x = 1.5 and y = 60
∴ xy = 1.5 × 60 = 90
⇒ k = 90
When y = 4.5, then from equation (i),
4.5 × y = k
⇒ 4.5 × y = 90 ...[Putting the value of k]
⇒ `y = 90/4.5 = 20`
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