Question

A merchant has 120 kg of rice. he sells a pact of it at a profit of 10% android the rest at a profit of 25%. he gains 15% on the whole. quantity of rice he sold at 25% gain is?

Answer 1

A merchant has 120 kg of rice. He sells a part of it at a profit of 10% and the rest at a profit of 25%

so, x kg of rice sold at 10% profit
(120 - x) kg of rice sold at 25% profit

so, total profit is 15% profit

15% of 120 = 10% of x + 25% of (120 - x)
15*120 = 10x + 25(120-x)
1800 = 10x + 3000 - 25x
1800-3000 = -15x
-1200 = -15x
x = 1200/15
x = 80

x = 80 kg of rice at 10% profit
120-x = 120-80 = 40 kg of rice at 25% profit

#mark as brainliest

Answer 2

Answer:  The required quantity of rice sold at 25% gain is 40 kg.

Step-by-step explanation:  Given that a merchant has 120 kg of rice. He sells a part of it at a profit of 10% and the rest at a profit of 25%. He gains 15% on the whole.

We are to find the quantity of rice he sold at 25% gain.

Let x kg be the quantity of rice that the merchant sold at 25% gain.

Then, the quantity of rice sold at 10 % gain = (120 - x) kg.

According to the given information, we have

$10\%\times (120-x)+25\%\times x=15\%\times 120\\\\\\\Rightarrow \dfrac{10}{100}\times (120-x)+\dfrac{25}{100}\times x=\dfrac{15}{100}\times120\\\\\\\Rightarrow \dfrac{120-x}{10}+\dfrac{x}{4}=18\\\\\\\Rightarrow \dfrac{240-2x+5x}{20}=18\\\\\Rightarrow 3x+240=360\\\\\Rightarrow 3x=120\\\\\Rightarrow x=\dfrac{120}{3}\\\\\Rightarrow x=40.$

Thus, the required quantity of rice sold at 25% gain is 40 kg.