The price of 10 chairs is equal to that of 4 tables. The price of 15 chairs and 2 tables is Rs. 4000. Find the total price of 12 chairs and 3 tables.

Correct option is A

Ans. (a)
Sol.
Let the price of one chair be x, and the price of one table be y.
From the question:
10 chairs = 4 tables → 10x = 4y → x = (2/5)y
15x + 2y = 4000
Substitute x = (2/5)y into equation 2:
15 × (2/5)y + 2y = 4000
⇒ (30/5)y + 2y = 4000
⇒ 6y + 2y = 4000
⇒ 8y = 4000
⇒ y = 500
Now, x = (2/5) × 500 = 200
Now calculate the cost of 12 chairs and 3 tables:
= 12x + 3y = 12×200 + 3×500 = 2400 + 1500 = Rs. 3900
Wait! This matches Rs. 3900, which is not option (a) but rather: