More Math!!

[CannonD]

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1. A creeper plant is climbing up and around a cylindrical [COLOR=blue ! important][COLOR=blue ! important]tree[/COLOR][/COLOR] trunk in a helical manner. The tree trunk has a height of 600 inches and a circumference of 40 inches.

If the creeper covers a vertical distance of 75 inches in one complete twist around the tree trunk, what is the total length of the creeper?

2.Grandpa:

"My grandson is about as many days as my son is weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 160 years. Can you tell me my age in years?"

 

[Streetwolf]

1. A creeper plant is climbing up and around a cylindrical [COLOR=blue ! important][COLOR=blue ! important]tree[/COLOR][/COLOR] trunk in a helical manner. The tree trunk has a height of 600 inches and a circumference of 40 inches.

If the creeper covers a vertical distance of 75 inches in one complete twist around the tree trunk, what is the total length of the creeper?

2.Grandpa:

"My grandson is about as many days as my son is weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 160 years. Can you tell me my age in years?"

1. (Edited) The trunk is 600 inches tall and it takes the creeper 75 inches vertically to loop around so it makes 8 full loops around. The circumference is 40 inches so it travels 320 inches (40x8) around the trunk. So the x-axis length is 320 inches. Of course it also travels up the trunk to the top (600 inches). The y-axis length is 600 inches. The hypotenuse is the answer you want which is the square root of (600^2 + 320^2) = 680 inches.

2. 'About as many' is horrible wording really, so I'm going to assume the values are equal. That means G (for grandson) = 1/7 S (for son). Why? Because for every day old that the grandson is, the son is 7 days old (1 week).

And finally G = 1/12 D (for dad, the narrator) because for every month old that the grandson is, the dad is 12 months old (1 year).

So you have G = 1/7 S and G = 1/12 D. You also have G + S + D = 160. So first rearrange the first two - S = 7G and D = 12G. Now fill in.

You have G + 7G + 12G = 160 or 20G = 160. So G = 8. The grandson is 8.

That means the son is 56 and the dad is 96.

Does this make sense? Well probably not in the real world but for the problem, yes.

 

[klutzy1987]

1. The trunk is 600 inches and every full turn of the creeper covers 75 of those inches. Since 600/75 = 8, the creeper makes 8 full turns around the trunk. The circumference is 40 inches which means one full revolution around the trunk covers 40 inches. Since the creeper travels around the trunk 8 times, it covers 40*8 = 320 inches.

2. 'About as many' is horrible wording really, so I'm going to assume the values are equal. That means G (for grandson) = 1/7 S (for son). Why? Because for every day old that the grandson is, the son is 7 days old (1 week).

And finally G = 1/12 D (for dad, the narrator) because for every month old that the grandson is, the dad is 12 months old (1 year).

So you have G = 1/7 S and G = 1/12 D. You also have G + S + D = 160. So first rearrange the first two - S = 7G and D = 12G. Now fill in.

You have G + 7G + 12G = 160 or 20G = 160. So G = 8. The grandson is 8.

That means the son is 56 and the dad is 96.

Does this make sense? Well probably not in the real world but for the problem, yes.

Im pretty sure that that is wrong. It asked for the length of the creeper and the creeper can not be longer that 115 which would be its length if you added the vertical and horozontal together (40+75). The answer lies somewhere between 75 and 115.something like 100 approximately. However 320 s definitely not the length of the creeper.

 

[Willem]

Yeah, the creeper thing has me stumped as well and I always figured that I was pretty good at these sort of things. I guess the best way to look at it would be to imagine it as a giant triangle. The triangle has a base of 320 (8 twists x 40in a twist) and a height of 600 (the height of the tree). Finding the hypotenuse would give the length of the creeper I believe? I dont ahve a calculator with me

Actually, I just clicked the link and the hint confirms as much that this is the way to solve it. Although, the problem on that webpage uses different numbers.

 

[CannonD]

Thank you streetwolf, the 2nd problem you got it right, and it does make sense. I think the 1st problem is kind of hard, and thanks to will's idea, i just figure it out. Thank you guys

 

[Streetwolf]

Sorry, did it in a rush. Will edit the original post.

Done. Check it again.

 

[joonkimdds]

The grandson is 8.

That means the son is 56 and the dad is 96.

Does that mean the dad was a virgin until he became 40 yrs old, and his son was a virgin until he became 48 yrs old?

What year is this problem made?

If this was the multiple choice question, 8,56,96 would be the first that I would've eliminated without even trying to solve the problem 🙂

 

[Streetwolf]

Some people out there do have sex without having a kid 9 months later.