In 150 litre, milk is 84%ie 150 x 84/100 = 126 litre Let us add x litres of waterTherefore, the quantity of mixture = 150 + x∴ 52.5% of (150 + x) = 126 litres 150 + x = 126x100/52.5 = 240 litres∴ x = 240 - 150 = 90 litres
S.P. per metre = 8200/40 = Rs. 205∴ C.P. per metre = Rs. (205 - 25) = Rs. 180∴ C.P. of 40 metre cloth= Rs. (40 x 180) = Rs. 7200∴ Gain = Rs. (8200 - 7200) = Rs. 1000