By what percentage is the cost price of drink 'P'

Solution

ATQ, (r - 100 + r + r + 100)/3 = 800 3r/3 = 800 r = 800 For Drink ‘P’, SP = 800 - 100 = 700 Rs. CP = 700 - (180 - a) = (520 + a) Rs. MP = 700 + (a + 60) = (760 + a) Rs. (520 + a) × 1.375 = 760 + a 715 + 1.375a = 760 + a 0.375a = 45 a= 120 For drink ‘Q’, SP = 800 Rs. CP = 800 - (160 - b) = (640 + b) Rs. MP = 800 + (b + 80) = (880 + b) Rs. (640 + b) × 4/3 = 880 + b 2560 + 4b = 2640 + 3b b = 80 For Drink ‘R’, SP = 800 + 100 = 900 Rs. CP = 900 - (200 - c) = (700 + c) Rs. MP = 900 + (c + 20) = (920 + c) Rs. (700 + c) × 1.275 = 920 + c 892.5 + 1.275Z = 920 + c 0.275c = 27.5 c = 100 Therefore, CP of drink ‘P’ = 520 + 120 = 640 Rs. CP of drink ‘R’ = 700 + 100 = 800 Rs. Hence, Required % = (800 - 640)/800 × 100 = 20%