If we used “a” tons of grade A and “b” tons of grade B we would get a + b tons of mixture. Converting to costs we get 36a + 24b = 33(a + b) 36a + 24b = 33a + 33b 36a - 33a = 33b - 24b 3a = 9b a = 3b This means the mixture contains 3 times as much of grade A than grade B The ratio of grade A : grade B = 3 : 1
For example if we mixed 3 tons of A with 1 ton of B we would get 4 tons of mixture The cost would be 3 x 36 + 1 x 24 = 108 + 24 = $132 for 4 tons = $33 per ton