Thread: Arithmetic Sequence Word Problem Grade 11

1. Boxes are stacked in a store display in the shape of a triangle. The numbers of boxes in the rows form an arithmetic sequence. There are 41 boxes in the 3rd row from the bottom, 32 boxes in the 12th row from the bottom. What is the maximum possible number of rows of boxes?
Can someone explain how to get this? Thanks

A: 23

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2. The time from one full moon to the next is 29.53 days. The first full moon of a year occurred 12.31 days into the year. At what time of the day did the 9th full moon occur?
I don't understand how to get the time... explain please and thank you

A: 13:12

There is just 1 less box as we go up the pile of boxes. 41 on the 3rd, 40 on the 4th, 39 on the 5th and so on.

In that case, how many is on the bottom. You can see now how high it is until we get to one box at the top.

Hello skeske1234

Originally Posted by skeske1234

2. The time from one full moon to the next is 29.53 days. The first full moon of a year occurred 12.31 days into the year. At what time of the day did the 9th full moon occur?

The second full month occurs 12.31 + 29.53 days into the year; the third 12.31 + 2 x 29.53 days, and so on. So the ninth occurs 12.31 + 8 x 29.53 = 248.55 days in.

Now, to get the time of day, we just look at the decimal part of this answer: 0.55. This is just over half a day, counting from midnight. To get the time of day, first multiply by 24 (why?). This will give you the hours part of the time, with a decimal bit left over. That's 13 point something - just after 1 p.m. Right? Finally, take the decimal part of this number and multiply it by ?? to turn hours into minutes. Can you get the answer 13:12?

Grandad