Question

if CP is 90% of SP . find profit percentage.

Answer 1

$let \: s.p \: = x \\ c.p \: = \frac{90}{100} \times x = \frac{9}{10} x$

$profit = x - \frac{9}{10} x \\ = > \frac{x}{10}$

$profit \: \% \: = \frac{ \frac{x}{10} }{ \frac{9x}{10} } \times 100\\ = > \frac{x}{10} \div \frac{9x}{10} \times 100 \\ = > \frac{x}{10} \times \frac{10}{9x} \times 100 \\ = > \frac{100}{9} \\ = > 11.111$