Math problem - what's your answer?

[Anonymous]

Anonymous wrote:

Anonymous wrote:45 minutes

+1. 5 mins/cut, 9 cuts to make 10 pieces.

+1

[Anonymous]

Anonymous wrote:

Anonymous wrote:45 is the obvious answer but OP said it's not the obvious answer, so what is it?

45 is the answer. I think OP thinks 40 would be the obvious answer.

According to my kid most of his 3rd grade AAP class thought the answer was 40.

[Anonymous]

Anonymous wrote:20 min = 5 pieces
X min = 10 pieces

40.

Takes him 2x as long for 2x the amount.

No.

20 min = 4 cuts (to get 5 pieces)
x min = 9 cuts (to get 10 pieces)

[Anonymous]

Anonymous wrote:

Anonymous wrote:20 min = 5 pieces
X min = 10 pieces

40.

Takes him 2x as long for 2x the amount.

OP here. This was my first thought, and my kid's. But everyone who said 45 minutes is in fact correct. 5 minutes per chop and 9 chops to get 10 pieces.

45 is clearly correct.

Draw the diagram. Show your work. Stop doing it in your head at this young age. (then as a grown-up mom you will get the question correct too!)

This is a very easy question.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:45 is the obvious answer but OP said it's not the obvious answer, so what is it?

45 is the answer. I think OP thinks 40 would be the obvious answer.

According to my kid most of his 3rd grade AAP class thought the answer was 40.

Is AAP for smart kids? If so, they should not do work in their heads yet = wrong answer.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:45 is the obvious answer but OP said it's not the obvious answer, so what is it?

45 is the answer. I think OP thinks 40 would be the obvious answer.

According to my kid most of his 3rd grade AAP class thought the answer was 40.

Is AAP for smart kids? If so, they should not do work in their heads yet = wrong answer.

Just shows Moms are still smarter.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:45 is the obvious answer but OP said it's not the obvious answer, so what is it?

45 is the answer. I think OP thinks 40 would be the obvious answer.

According to my kid most of his 3rd grade AAP class thought the answer was 40.

Well most of those kids are probably in advanced classes because mommy harassed the school...not because they are actually...smart.

[Anonymous]

My kids answered: It depends. Is he in shape? Does he need a break to do more cuts? Is it the same size log and if so is it more difficult to cut it into smaller pieces versus larger pieces? And if it isn't the same size log, does it take longer to manipulate the larger log in the first place?

Sigh. Maybe this kid will get better grades in physics some day? Or become a lawyer.

[Anonymous]

I think it is easy except I could see a kid confusing the number of cuts needed to get 5 or 10 pieces (and incorrectly thinking it is 5 or 10 cuts.) If they aren't tripped up by that, the problem is very easy.

[Anonymous]

I admit I got tripped up by the number of cuts he would need. Once you realize the number of cuts is 1 fewer than the number of pieces, it's easy.

[Anonymous]

Anonymous wrote:My kids answered: It depends. Is he in shape? Does he need a break to do more cuts? Is it the same size log and if so is it more difficult to cut it into smaller pieces versus larger pieces? And if it isn't the same size log, does it take longer to manipulate the larger log in the first place?

Sigh. Maybe this kid will get better grades in physics some day? Or become a lawyer.

This is exactly how I was answering it too. I overanalyze everything and wouldn't have even thought of this as a math problem in the first place.

[Anonymous]

Anonymous wrote:You might want to factor in how tired Mr. Sawyer gets. The rate of work slows down as production increases.

On the other hand, he's dealing with lighter pieces so it might be easier.

Honestly, I feel like 17 of those 20 minutes are going to be putting gas in the chainsaw, and getting it out of the garage in the first place.

[Anonymous]

45 minutes

[Anonymous]

Anonymous wrote:

Anonymous wrote:My kids answered: It depends. Is he in shape? Does he need a break to do more cuts? Is it the same size log and if so is it more difficult to cut it into smaller pieces versus larger pieces? And if it isn't the same size log, does it take longer to manipulate the larger log in the first place?

Sigh. Maybe this kid will get better grades in physics some day? Or become a lawyer.

This is exactly how I was answering it too. I overanalyze everything and wouldn't have even thought of this as a math problem in the first place.

Those are not remotely good answers to a CML. The answer line is a small little line.

[Anonymous]

Every cut takes 5 minute. Now draw a log and make enough cuts to have 10 pieces. Count how many cuts (9) it took to make ten pieces and then x 5 minutes for each cut. 9x5+45
This is a problem a kid should be able to figure out with pen and paper.
Seems like a pattern to me:
4 cuts, 5 pieces.
9 cuts, 10 pieces.
19 cuts, 20 pieces.