Arun buys one kilogram of apples for Rs. 120 and sells it to Swati gaining 25%. Swati sells it to Divya who again sells it for Rs. 198, making a profit of 10%. What is the profit percentage made by Swati ?

In 1st transaction,

Cost price for Arun = Rs. 120

Profit % = 25%

=> Selling price = $$120+(\frac{25}{100}\times120)$$

= $$120+30=Rs.$$ $$150$$

In 3rd transaction,

Selling price by Divya = Rs. 198

=> Profit % = 10%

=> Cost price for Divya = $$\frac{198}{(100+10)}\times100$$

= $$\frac{198}{11}\times10=Rs.$$ $$180$$

Now, in 2nd transaction,

Cost price for Swati = Rs. 150

Selling price for Swati = Rs. 180

=> Profit % = $$\frac{(180-150)}{150}\times100$$

= $$\frac{30}{1.5}=20\%$$

=> Ans - (B)