Correct Answer - Option 1 : Rs. 813
Given:
Cost of 4 tables and 9 chairs combined = Rs. 1285.
Profit calculated which he will earn = Rs. 157
Formula used:
SP = CP × [(100 + Gain%)/100]
Calculation:
Let CP of 1 table and 1 chair be Rs. x and Rs. y resepctively.
Now Acc. to Question,
4x + 9y = 1285 ----(i)
and, 10% of 4x + 20% of 9y = 157
4x + 18y = 1570 ----(ii)
Now 2 × (i) – (ii)
(8x+18y) – (4x + 18y) = 2570 – 1570
⇒ 4x = 1000
⇒ x = 250 (price of 1 table)
Now, From eqn. (i)
⇒ 4 × 250 + 9y = 1285
⇒ 9y = 285
⇒ y = 285/9 (price of 1 chair)
Combined money which Rakesh will pay for 3 tables and 2 chairs = 3 × 250 + [(2 × 285)/9]
⇒ Rs. (750 + 63.33)
⇒ Rs. 813.33 ≈ Rs. 813
∴ The required amount is Rs. 813