Question

The cost price of 16 books is equal to the selling price of 30 books. Find the gain per cent.
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Answer 1

Let the SP of 1 book = Rs 1

SP of 16 books = Rs 16

CP of 16 books = SP of 30 books

= Rs 30

SP of 30 books = CP of 16 books

= Rs 16

So, CP > SP

Loss = CP –SP

= 30 – 16

= Rs 14

$loss\% = \frac{loss}{c.p} \times 100 \\ loss\% = \frac{14}{30} \times 100 \\ loss\% = \frac{140}{3}\% \\ = 46 \frac{2}{3}$