 Hi and welcome to the session. I am Shashi. Let us do one question. Question is form the pair of linear equations for the following problems and find their solution by substitution method. Question is the coach of a cricket team buys 7 bats and 6 balls for Rs. 3800. Later she buys 3 bats and 5 balls for Rs. 1750. Find the cost of each bat and each ball. Let us start with the solution now. We can see there are two quantities unknown in the question that is the cost of each bat and the cost of each ball. So let us assume cost of 1 bat is equal to Rs. x, cost of 1 ball is equal to Rs. y. According to the question the coach of a cricket team buys 7 bats and 6 balls for Rs. 3800. So you know cost of 7 bats would be 7 x and the cost of 6 balls would be 6 y. Now cost of 1 bat is equal to Rs. x. So the cost of 7 bats would be equal to 7 x. Cost of 1 ball is equal to Rs. y. So the cost of 6 balls is equal to Rs. 6 y. So we get 7 x plus 6 y must be equal to 3800. Let us name this equation as 1. Now second condition given in the question is that she buys 3 bats and 5 balls for Rs. 1750. We know cost of 3 bats and the cost of 5 balls is equal to Rs. 1750 as given in the question. So cost of 3 bats would be equal to 3 x. As cost of 1 bat is equal to Rs. x. So the cost of 3 bats would be equal to 3 x. Now the cost of 1 ball is equal to Rs. y. So the cost of 5 balls would be equal to 5 y. So we get the equation 3 x plus 5 y is equal to 1750. Let us name this equation as 2. Now from equation 1 we get this is equal to 3800 minus 6 y upon 7. Now let us name this equation as 3. Now we will substitute this value of x in equation 2. Now substituting the value of x from equation 3 in equation 2 we get 3 multiplied by 3800 minus 6 y upon 7 plus 5 y is equal to 1750. Now multiplying both sides of the equation by 7 we get 3 multiplied by 3800 minus 6 y plus 35 y is equal to 1750 multiplied by 7. Now this is further equal to 11400 minus 18 y plus 35 y is equal to 12250. This implies 17 y is equal to 12250 minus 11400. Or we can say 17 y is equal to 850. This further implies y is equal to 850 divided by 17 which is equal to 15. Therefore we get y is equal to 15. Now we will substitute this value of y in equation 3 to get the value of x. Now substituting y is equal to 15 in equation 3 we get x is equal to 3800 minus 6 multiplied by 50 upon 7. Now this implies x is equal to 3800 minus 300 upon 7. This implies x is equal to 3500 upon 7. Or we can write x is equal to 500. Now the cost of 1 bar is equal to rupees x is equal to rupees 500 and the cost of 1 bar is equal to rupees y is equal to rupees 50. So our required equations are 7x plus 6 y is equal to 3800 and 3x plus 5 y is equal to 1750 where x and y are the cost in rupees of 1 bar and 1 bar respectively. Solution of the equations is x is equal to 500 and y is equal to 50. This completes the session. Hope you understood the session. Take care and good bye.