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Question
A photocopy store charges ₹ 1.50 per copy for the first 10 copies and ₹ 1.00 per copy after the 10th copy. Let x be the number of copies, and let y be the total cost of photocopying. Find the cost of making 40 copies
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Solution
When x = 10
y = 1.50 × x
⇒ y = 1.50 × 10
= 15
The corresponding point is (10, 15)
When x = 20
y = x + 5
⇒ y = 20 + 5
= 25
The corresponding point is (20, 25)
When x = 30
y = x + 5
⇒ y = 30 + 5
= 35
The corresponding point is (30, 35)
When x = 40
y = 40 + 5
= 45
The corresponding point is (40, 45)
When x = 50
y = 50 + 5
= 55
The corresponding point is (50, 55)
The cost of 40 copies is the value of y
When x = 40
y = 40 + 5
= 45 rupees
Cost of 40 copies = 45 rupees
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