Reasoning and answer: The cost of the mangoes is 6 mangoes $3 / mango = $18. The cost of the apple juice is 6 cartons $3 / carton = $18. Find the total cost of the groceries which is $18 + $18 = $36. Rihanna has $50 $36 = $14 left.
The answer: 14
What was the question?
Question: Rihanna has $50 to go to the supermarket. Rihanna bought 6 mangoes and 6 cartons of apple juice. Each mango cost $3 and each carton of apple juice cost $3. How much money does Rihanna have left?

Reasoning and answer: After buying 3 pieces of gum Ariana has 10 + 3 = 13 pieces of gum. After giving her 11 friends gum Ariana has 13 - 11 = 2 pieces of gum left.
The answer: 2
What was the question?
Question: Adrianna has 10 pieces of gum to share with her friends. There wasn't enough gum for all her friends, so she went to the store to get 3 more pieces of gum. She gave out gum to 11 friends. How many pieces of gum does Adrianna have now?

Reasoning and answer: There will be a total of (1) Brian + (1) Brian's wife + (2) two kids + (2) Brian's parents + (2) Brian's in - laws = 1 + 1 + 2 + 2 + 2 = 8 people eating. If 1 person eats 2 serving of lasagna then 8 people will eat 8 * 2 = 16 servings. If each serving requires 1 / 2 cup of milk then 16 servings require 16 * 1 / 2 cups = 8 cups of milk. If one cup of milk equals 250 ml, then 8 cups of milk equal 8 * 250 = 2000 ml of milk. 1L carton of milk equals 1000ml of milk, therefore Brian needs 2000 / 1000 = 2 cartons of 1L milk.
The answer: 2
What was the question?
Question:
One US cup equals 250ml. Brian is making lasagna for himself, his wife, his two kids, his parents, and his wife's parents. The recipe requires 1/2 a cup of milk per serving. How many 1L cartons of milk does Brian need to buy if each person is expected to eat 2 servings?