a manufacturer sells a bottle of fruit juice to a trader at a profit of 40%. The trader sells it for 84 at a profit of 20%. Find the traders buying price and the cost of manufacture of one bottle
original cost price --- x
selling price ----- 1.4x
new selling price = 1.2(1.4x) = 1.68x
1.68x - 1.4x = 84
.28x = 84
x = 300
check:
original cost price = 300
selling price = 1.4(300) = 420
new selling price = 1.2(420) = 504
profit of 2nd trader = 504-420 = 84
all is good!