Oranges are bought at the rate of 10 for $25 and sold at the rate of 9 for $25. The profit is:

a) \(9 \frac{1}{11}\) %

b) \(10\)%

c) \(11 \frac{1}{9}\) %

d) \(12 \frac{1}{2}\) %
e) \(2 \frac{1}{2}\) %

Cost price = the rate of 10 for $25= \(\frac{25}{10}\) and
Selling price = sold at the rate of 9 for $25= \(\frac{25}{9}\)
Profit = \((\frac{25}{9}-\frac{25}{10})/\frac{25}{10}=\frac{25}{90}/\frac{25}{10}=\frac{1}{9}\)
Profit % = \(100*\frac{1}{9}\)= \(11 \frac{1}{9}\) %

C
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Some useful Theory.
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