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Question
If a, 12, 16 and b are in continued proportion find a and b.
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Solution
∵ a, 12, 16, b are in continued proportion, then
`a/(12) = (12)/(16) = (16)/b`
⇒ `a/(12) = (12)/(16)`
⇒ 16a = 144
⇒ a = `(144)/(16)` = 9
and `(12)/(16) = (16)/b`
⇒ 12b = 16 x 16 = 256
b = `(256)/(12) = (64)/(3) = 21(1)/(3)`
Hence a = 9, b = `(64)/(3) or 21(1)/(3)`.
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