Cost of 10 shirts and 12 pants is Rs. 7,800 and the cost

Solution

ATQ, Let the cost of a shirt and a pant be Rs. 'a' and Rs. 'b', respectively. So, 10a + 12b = 7,800 ---------- (I) And, 8a + 11b = 6,450 ---------- (II) On solving, 4 X equation (I) and - 5 X equation (II), we get, 4 X (10a + 12b) - 5 X (8a + 11b) = 4 X 7,800 - 5 X 6,450 Or, 40a + 48b - 40a - 55b = 31,200 - 32,250 Or, -7b = -1,050 So, 'b' = 150 On putting the value of 'b' in equation (I), we get, 10a + 12 X 150 = 7,800 Or, 10a = 7,800 - 1,800 Or, 10a = 6,000 So, 'a' = 600 Therefore, required cost = (5a + 4b) = 5 X 600 + 4 X 150 = 3,000 + 600 = Rs.3,600