A business man mixed high quality sugar costing 10 shillings with low quality sugar costing 8 shillings per kg in the ratio 3:5 by which he sold the mixture at 9.80 shillings per kg. What was his percentage profit?

His percentage profit is 12%

Step-by-step explanation:

Here, we want to calculate the percentage profit made by the business man.

Per kg of what he is selling, he has 3 parts high quality sugar and 5 parts low quality sugar.

Now let's see how much these costs

For the high quality sugar, it's total kg mixed per kg will be 3 / (3+5) = 3/8

Since high quality sugar costs 10 shillings per kg, 3/8 of a kg will cost 3/8 * 10 = 30/8 = 3.75 shillings

For the low quality, its part will be 5 / (3 + 5) = 5/8

since low quality costs 8 shillings per kg, 5/8 of a kg will cost 5/8 * 8 = 5 shillings

Total cost price = 3.75 + 5 = 8.75 shillings

% profit = (selling price - cost price) / cost price * 100%

selling price here is 9.8 shillings per kg

while cost price is 8.75 shillings per kg

% profit = (9.8-8.75) / 8.75 * 100%

= 1.05/8.75 * 100% = 0.12 * 100% = 12%