Which is the correct histogram for the data set of time spent riding bikes?

Write the summation to estimate the area under the curve y = 1 + x2 from x = -1 to x = 2 using 3 rectangles and right endpoints

40) linda was making chocolate truffles for the first day of school. the recipe for 20 chocolate truffles is: i cup of cream 2 cups of dark chocolate she noticed this will not be enough truffles for the 42 sure that all students in each homeroom next year. to be sure that all students receive a truffle, linda must adjust her recipe. a. complete the recipe for 42 truffles cups of cream - cups of dark chocolate work:

Can someone show me step by step how to do this?