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Question
The three scales below are perfectly balanced if • = 3. What are the values of ∆ and * ?
| (a) |  |
| (b) |  |
| (c) |  |
Solution
Given that • = 3 ...(i)
- 5* = 2Δ + 2• ...(ii)
- 2Δ = 2* + 2• ...(iii)
- 3* + 3• = 3Δ ...(iv)
Putting the value of (iii) in (ii), we get
5* = 2* + 2• + 2•
⇒ 5* – 2* = 4•
⇒ 3* = 4 × 3 ...[Using (i)]
⇒ * = `(4 xx 3)/3` = 4
Putting the value of * and • in (iv), we get
3 × 4 + 3 × 3 = 3Δ
⇒ 3Δ = 21
⇒ Δ = `21/3`
⇒ Δ = 7
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