Question

The cost of four cycle tyres and three tubes is Rs. 720, whereas the cost of the three cycle tyres and four tubes is Rs. 610. What is the cost of a tube?
1. Rs. 50
2. Rs. 42
3. Rs. 45
4. Rs. 40

Answer 1

Correct Answer - Option 4 : Rs. 40

Let the cost of one cycle tyre be x, and the cost of one tube be y.

Here, The cost of four-cycle tyres and Three tubes is Rs. 720, and The cost of three cycle tyres and four tubes is Rs. 610.

So, 4x + 3y = 720      -----(1)

3x + 4y = 610      ----(2)

Multiplying equation (1) by 3 and equation (2) by 4,

12x + 9y = 2160     ----(3)

12x + 16y = 2440     ----(4)

Subtracting equation (3) from equation (4),

7y = 280

⇒ y = 40

Here, y is the cost of one tube.

Hence, the cost of a tube is "Rs. 40".