By mixing two brands of tea and selling the mixture at the rate of Rs. 177 per kg, a shopkeeper makes a profit of 18% . If to every 2 kg of one brand costing Rs. 200 per kg, 3 kg of the other brand is added, then how much per kg does he other brand cost ?

Solution(By Examveda Team)

Let the cost of the other brand be Rs. x per kg.
C.P. of 5 kg = Rs. (2 × 200 + 3 × x) = Rs. (400 + 3x)
S.P. of 5 kg = Rs. (5 × 177) = Rs. 885
$$\eqalign{ & \therefore \frac{{885 - \left( {400 + 3x} \right)}}{{400 + 3x}} \times 100 = 18 \cr & \Leftrightarrow \frac{{485 - 3x}}{{400 + 3x}} = \frac{9}{{50}} \cr & \Leftrightarrow 24250 - 150x = 3600 + 27x \cr & \Leftrightarrow 177x = 20650 \cr & \Leftrightarrow x = \left( {\frac{{350}}{3}} \right) = 116\frac{2}{3} \cr & {\text{So, cost of the other brand}} \cr & = {\text{Rs}}{\text{. }}116.66 \cr} $$