Question

Q.8 - An article is sold at 25% profit. If the CP and the SP of the article
are increased by Rs 60 and Rs 30 respectively, the profit% decreases
by 15%. Find the cost price of the article.​

Answer 1

Given  : An article is sold at 25% profit. CP and the SP of the article

are increased by Rs 60 and Rs 30

To find : cost price of the article.​

Explanation:

profit %

$P = \frac{SP-CP}{CP}\times 100\\\\here ,p = 25\\\\25 = \frac{SP-CP}{CP}\times 100\\\\solving\\\\SP-CP = \frac{CP}{4}..(1)$

now , CP and the SP of the article  are increased by Rs 60 and Rs 30

therefore , the profit %  decreases by 15% i.e it becomes 10%

thus

new profit % = 10%

now ,

accordingly

$\frac{(SP+100)-(CP+60)}{CP+60}\times 100 = 10\\\\\frac{SP+30-CP-60}{CP+60} = \frac{10}{100}\\\\\frac{SP-CP-30}{CP+60} = \frac{1}{10}\\\\\text{using 1 we get}\\\\\frac{CP}{4}-30 = \frac{CP}{10}+6\\\\\frac{CP}{4}-\frac{CP}{10} = 30+6\\\\6CP = 36\times 40\\\\CP = \frac{36\times 40}{6}\\\\CP = 240$

hence , The cost price of the article is Rs. 240