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Question
If a and b vary inversely to other, then find the values of p, q, r ; x, y, z and l, m, n.
| a | 6 | 8 | q | 25 |
| b | 18 | p | 39 | r |
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Solution
If a and b vary inversely to other.
i.e. ab = k ...(Constant)
For table,
| a | 6 | 8 | q | 25 |
| b | 18 | p | 39 | r |
If a = 6 and b = 18
Then, a × b = 6 × 18 = 108
⇒ k = 108
When a = 8 and b = p, then
ab = k
⇒ 8 × p = 108
⇒ p = `27/2`
When a = q and b = 39, then
ab = k
∴ q × 39 = 108
⇒ q = `108/39 = 36/13`
When a = 25 and b = r, then
ab = k
⇒ 25 × r = 108
⇒ r = `108/25`
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