93.8k views
5 votes
On the first day of school, Ms. Dubacek gave her third-grade students 

6 new spelling words to learn. On each day of school after that, she gave the students 3 new spelling words. How many new spelling words had she given the students by the end of the 21st day of school?

2 Answers

5 votes

Answer:

Explanation:

On the first day, Ms. Dubacek gave 6 new spelling words.

On each subsequent day, she gave an additional 3 new spelling words.

Therefore, on the second day of school, she gave a total of 6 + 3 = 9 new spelling words.

On the third day of school, she gave a total of 6 + 3 + 3 = 12 new spelling words.

We can see a pattern emerging here: on each day, she gives 6 more words than the previous day.

So on the 21st day of school, she will have given a total of:

6 + (9 + 12 + 15 + ... + 60)

To find the sum of this arithmetic series, we can use the formula:

S = n/2 * (a + l)

where:

S = the sum of the series

n = the number of terms in the series

a = the first term in the series

l = the last term in the series

In this case, we have:

n = 19 (since we're counting from the second day of school to the 21st day)

a = 9 (since that was the total number of spelling words given on the second day)

l = 60 (since that will be the total number of spelling words given on the 21st day)

So, plugging in these values, we get:

S = 19/2 * (9 + 60) = 19/2 * 69 = 655.5

Therefore, by the end of the 21st day of school, Ms. Dubacek will have given her students a total of 6 + 655.5 = 661.5 new spelling words (rounded to the nearest whole number, this is 662).

User Ciscoheat
by
8.1k points
3 votes

Answer: 126 Spelling Words

Step-by-step explanation: I got that because you had to multiply 6 by 21 and you get 126.

User Vdaubry
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories