High School

The cost of 5 tables and 2 chairs is Rs 3700, while the cost of 2 tables and 5 chairs is Rs 2950. Find the cost of 3 tables and 3 chairs.

Answer :

To solve this problem, we can use a system of equations. Let's denote:


  • [tex]x[/tex] as the cost of one table

  • [tex]y[/tex] as the cost of one chair


We are given the following two equations based on the problem statement:

[tex]5x + 2y = 3700[/tex]

[tex]2x + 5y = 2950[/tex]

We want to find the cost of 3 tables and 3 chairs, which means we need to find the value of [tex]3x + 3y[/tex].

Step 1: Solve the system of equations

First, let’s solve the system of equations to find [tex]x[/tex] and [tex]y[/tex].

Start with the two equations:


  1. [tex]5x + 2y = 3700[/tex]

  2. [tex]2x + 5y = 2950[/tex]


We can use the method of substitution or elimination. Here, we'll use elimination because it seems easier to eliminate a variable by making coefficients equal.

Let's eliminate [tex]x[/tex] by making the coefficients of [tex]x[/tex] in both equations equal. Multiply Equation 1 by 2 and Equation 2 by 5:

[tex]10x + 4y = 7400[/tex]

[tex]10x + 25y = 14750[/tex]

Now subtract the first new equation from the second:

[tex](10x + 25y) - (10x + 4y) = 14750 - 7400[/tex]

[tex]21y = 7350[/tex]

Divide both sides by 21:

[tex]y = \frac{7350}{21}[/tex]

[tex]y = 350[/tex]

Step 2: Substitute to find [tex]x[/tex]

Now that we know [tex]y = 350[/tex], substitute this back into one of the original equations to find [tex]x[/tex].

Use the first equation:

[tex]5x + 2(350) = 3700[/tex]

[tex]5x + 700 = 3700[/tex]

Subtract 700 from both sides:

[tex]5x = 3000[/tex]

Divide by 5:

[tex]x = 600[/tex]

Step 3: Calculate the cost of 3 tables and 3 chairs

Now, with [tex]x = 600[/tex] and [tex]y = 350[/tex], we can find the cost of 3 tables and 3 chairs:

[tex]3x + 3y = 3(600) + 3(350)[/tex]

[tex]= 1800 + 1050[/tex]

[tex]= 2850[/tex]

Thus, the cost of 3 tables and 3 chairs is Rs 2850.