David is making rice for his guests based on a recipe that requires rice, water, and a special blend of spice, where the rice-to-spice ratio is 15:1. He currently has 40 grams of the spoce blend, he can go buy more if necessary. He wants to make 10 servings, where each serving has 75 grams of rice. Overall, David spends $4.50 on rice. What is the price of rice per gram? HELPPP

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.