We have a question: Miriam currently has 30 marbles, but she used to have more. Miriam gave her brother 60 marbles, gave her sister twice that amount and gave her friend Savanna three times the amount she currently has. How many marbles did Miriam start with?
And an answer: 300
So how you got the answer?
If Mariam remains with 30 marbles after giving her brother 60 marbles, she had 30 + 60 = 90 marbles. Mariam's sister receives twice as many marbles as her brother, a total of 2 * 60 = 120 marbles. The total number of marbles before giving any to her brother or sister is 120 + 90 = 210. Savannah is to receive three times as many marbles as Mariam has to remain with, a total of 3 * 30 = 90 marbles. Before giving out any marble, Mariam has 210 + 90 = 300 marbles.

We have a question: Stefan, Vail, and Aiguo collected seashells. Stefan had 16 more seashells than Vail. Vail had 5 less than Aiguo. Aiguo had 20 seashells. How many seashells did the 3 children have in total?
And an answer: 66
So how you got the answer?
Aiguo = 20 shells. Vail = 20 - 5 = 15 shells. Stefan = 15 + 16 = 31 shells. Total = 20 + 15 + 31 = 66. The 3 children had 66 seashells altogether.

We have a question: Betty and Dora started making some cupcakes at the same time. Betty makes 10 cupcakes every hour and Dora makes 8 every hour. If Betty took a two-hour break, what is the difference between the number of cupcakes they made after 5 hours?
And an answer: 10
So how you got the answer?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Dora made 8 cupcakes per hour for 5 hours for a total of 8 * 5 = 40 cupcakes. Betty took a 2 - hour break so she spent 5 - 2 = 3 hours making cupcakes. Betty made 10 cupcakes per hour for 3 hours for a total of 10 * 3 = 30 cupcakes. The difference between the number of cupcakes they made is 40 - 30 = 10 cupcakes.