Suzy is the little girl that lives down the street. She loves collecting flowers from the meadows not far from their home. Crystal, her older sister, adores her and fondly follows her around.
On Monday she collected 50 flowers, and on Tuesday she collected 70 flowers, then on the day after that, she collected 90 of them. During the early mornings of Thursday, Suzy dared her sister to do something.
I dare you to guess how many flowers I'll have by the end of this week, big sis! Then tell me your answer on Sunday!
Crystal thought about the answer carefully. Then she noticed a pattern between the numbers 50, 70, and 90 and as a 10th grade student, her mind immediately went to arithmetic equations and series. She quickly solved the problem.
On Sunday....
What?! How did you know?
Wow, that so cool! You're so smart big sis!
Well then, little sister. i have my answer...you have a total of 770 flowers with you.
I used the Arithmetic series to solve the problem.