The three scales below are perfectly balanced if • = 3. What are the values of ∆ and *?
Solution:
It is given that
• = 3 …. (1)
5 * = 2 ∆ + 2 • ….. (2)
2 ∆ = 2 * + 2 • …. (3)
3 * + 3 • = 3 ∆ …. (4)
Substituting the value of (3) in (2)
5 * = 2 * + 2 • + 2 •
By further calculation
5 * - 2 * = 4•
By using equation (1)
5 * - 2 * = 4 × 3
3* = 4 × 3
* = (4 × 3)/3
* = 4
Substituting the value of * and • in equation (4)
3 × 4 + 3 × 3 = 3 ∆
3 ∆ = 21
Dividing both sides by 3
∆ = 21/3
∆ = 7
Therefore, the values of ∆ and * are 7 and 4.
✦ Try This: Priya got ₹ 12,500 as her monthly salary and over-time. Her salary exceeds the over-time by ₹ 5,000. What is her monthly salary ?
☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 4
NCERT Exemplar Class 7 Maths Chapter 4 Problem 106
The three scales below are perfectly balanced if • = 3. What are the values of ∆ and *?
Summary:
The three scales below are perfectly balanced if • = 3. The values of ∆ and * are 7 and 4
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