Ashopkeeper buys two types of tea one at $20 for 10 kg and the other at $23 for 10 kg. he mixes the two types and the mixture is sold at $38 for 10 kg. what will be his percentage profit?

Let us take the case of first type of tea
Cost of 10 kg of tea one = $20
Then
Cost of 1 kg of tea one = (20/10) dollars
                                     = 2 dollars
Now let us take the case of the second kind of tea
Cost of 10 kg of tea = $23
Then
Cost of 1 kg of tea = (23/10) dollars
                               = 2.3 dollars
So
The mixture of 1 kg of tea one
and 1 kg of second type of tea will cost = (2.0 + 2.3) dollars
                                                                = 4.3 dollars
Then the cost of 2kg mixture of tea costs = 4.3 dollars
So
The cost of 10 kg mixture will cost = (4.3/2) * 10 dollars
                                                         = 4.3 * 5 dollars
                                                        = 21.5 dollars
Then
The amount of profit made by selling 10 kg tea at $38 = (38 - 21.5) dollars
                                                                                       = 16.5 dollars
So
Percentage of profit made = (16.5/21.5) * 100
                                           = 1650/21.5
                                           = 76.74 percent
So the percentage of profit made is 76.74%.