Maria sells magazines for 4 days, selling 3 mags. on day 1, 6 on day 2 10 on day 3 and 15 on day 4.At this rate, how many will be sold in all in 7 days?

Question

I tried to shorten the question. My daughter is in 3rd grade and has this 1 math question for homework and I'm trying to help her. I don't understand the jump from day 2 to day 3. I'm not trying this again. I hope you can understand it. It won't let me try to shorten it without doing the whole thing over.

 

Answer 1

Hi Louvonne,

 

day 1 - 3

day 2 - 6

day 3 - 10

day 4 - 15

 

If you look at the difference between each day you will see a pattern

 

3, 4, 5   (difference between days

 

keep it going

 

day 5 - 21          (difference 6

day 6 - 28          (difference 7

day 7 - 36          (difference 8

 

now add the numbers for each day to get the total sold

 

Hope this helps

Answer 2

The sequence is 3, 6, 10, 15.

 

The difference between day 1 and day 2 is 3.

The difference between day 2 and day 3 is 4.

The difference between day 3 and day 4 is 5

 

So the DIFFERENCE from one day to the next is increasing each day.  With that pattern, the rest of the week will be

 

day 5: day 4 + 6 = 15 + 6 = 21

day 6: day 5 + 7 = 21 + 7 = 28

day 7: day 6 + 8 = 28 + 8 = 36

 

So if you add all the days together, you get 3 + 6 + 10 + 15 + 21 + 28 + 36 = 119