The price of 10 chairs is equal to that of 4 tables. The price of 15 chairs and 2 tables together is Tk. The total price of 12 chairs and 3 tables is:

A Tk. 3500

B Tk. 3750

C Tk. 3840

D Tk. 3900

Correct Answer: Option D

Let the cost of a chair and that of a table be Tk. x and Tk. y respectively.

Then, 10x = 4y or y = (5/2)x

So, 15x + 2y = 4000

=> 15x + 2 x (5/2)x = 4000

=> 20x = 4000

So, x = 200.

So, y = ((5/2) x 200) = 500.

Hence, the cost of 12 chairs and 3 tables = 12x + 3y

= Tk. (2400 + 1500)

= Tk. 3900.