1. The problem statement, all variables and given/known data A grocer sells items by mixing small stones into grains. He has 50 kg each of two varieties of rice. He mixes 7.5 kg of stones in all. For one kg of rice, he mixes 100 grams of stones in the first variety and the remaining in the other. Peter purchases 5 kg of rice of each variety from the grocer. Approximately, what is the actual percentage of grain that Peter has? 2. Relevant equations 3. The attempt at a solution Does this line mean that he mixes 7.5 kg into 100 kg of rice i.e 50 kg of 1st variety and 50 kg of second. I did not understand the above statement. What does it mean? Given Solution : 107.5 grams of total quantity has 100 grams of actual grains. Peter purchases 5 kg of each type. Hence, actual grains in 10 g = 10 * 100/107.5 close to 93. So, the required percentage is 93. Even the given solution is not clear to me. Help please.