markngolf Loc: Bridgewater, NJ

I was very surprised at the number of posts to Jerry's simple mathematical expression.
Apparently, there is more than a casual interest in mathematical puzzles, problems, ...

BTW: (an aside) - I taught mathematics for 37 years in NJ - 11 years in Jr. High, 26 years in HS. I began my teaching career after my discharge from the US Army in 1960. I was very instrumental in bringing "New Mathematics" to the 7th & 8th grades. The mathematics was not new, the inclusion of some topics in the curriculum was new and some of the teaching approaches were new. The mathematics was old!!!

So, here are a few more mathematics challenges:

1. 3 men enter a hotel to rent a room for the night. (Yes, this was a very long time ago). They go up to the desk clerk and ask the price for one night. The clerk indicates $30. Each man places a $10 bill on the counter and proceeds to the room. (Please, no comments about where they will sleep, how they will sleep, are they Gay, ...). After they leave, the desk clerk realizes he over charged them $5 for the room. He explains to the bellhop (many of you are way too young to know what that is - so Google it or ask Jerry) about the over charge and hands him a five dollar bill to return to the 3 men.

The bellhop is a bit dishonest and sees a way to make a few dollars. He knocks on the door of the room and explains about the overcharge and hands them each a $1 bill.
So, each man paid $9 for the room. 3 men - so 3 x $9 + $2 the bellhop kept = $29. What happened to the other dollar?

2. Why are manhole covers round (circular)? (The answer is NOT because the holes are round(circular).

3. You are given 3 buckets with no markings on the sides. The capacities are 3 gal., 5 gal. and 8 gal. A faucet is available with no limit of water.
a. How to you obtain (EXACTLY) 4 gallons of water? EXACTLY 7 gallons of water?

I hope this was fun!
Mark

Largobob

Mark,

I love mathematics....taught Physics (high school and Jr. College) for 35 years. These are LOGIC problems involving numbers....not true mathematics. Right?

DaveO Loc: Northeast CT

Hopefully we will not miss the intent of the original post.

BassmanBruce Loc: Middle of the Mitten

Fill the fiver and use it to fill the three gl, pour remaining into 8 gal. Repeat, walla, four gallons.

Manhole cover is only shape cover cannot fall into manhole.
Left some fun for others.

Edit: forgot to mention, Thanks, I enjoyed.

ricko49 Loc: Louisville, KY

1. They originally paid $30, but the clerk refunds $5, so the total paid is $25. The bellhop gives each one $1, which totals $3, and keeps $2 for himself. $25+$3+$2=$30.

2. A circular cover can't fall through it's own hole(thanks google!). There are other reasons, too.

3. Fill the 5 gallon bucket, then pour it into the 3 gallon bucket, leaving 2 gallons. Pour that into the 8 gallon bucket, which now contains 2 gallons. Repeat, and you have 4 gallons in the 8 gallon bucket.
Fill the 5 gallon bucket again, fill the 3 gallon bucket from that, and pour the remaining 2 gallons into the 8 gallon bucket. Then fill the 5 gallon bucket and pour into the 8 gallon bucket, giving you 7 gallons.

PixelStan77 Loc: Vermont/Chicago

My wife taught Math in East Brunswick when we were married in in 1962. I worked at RCA in Somerville and we lived in Bound Brook. You and her would enjoy talking about the old days. I remember going to her open school night when she talked about the Magic Square for teaching Math. She went back to teaching when our kids were 15.

foodie65

1. the fallacy here is that the men paid $27 (3x$9) when in act only $25 was paid to the clerk

markngolf Loc: Bridgewater, NJ

I taught in Middletown, 60 - 66, Watchung, 66 - 71 Chatham Twp/Chatham 71 - 97. I loved it and actually miss it. Oh yes, good old magic squares!! My wife was also a mathematics teacher in Scotch Plains.
Mark

markngolf Loc: Bridgewater, NJ

Yes, I guess they are.
Mark

Longshadow Loc: Audubon, PA, United States

1. later...

2. The round lid will not go through the hole, even on edge.

3a. Fill the five, pour it into the three, pout the remainder (2) into the 8,
do this twice. Now you have four in the 8 bucket.

3b. Figure based on the philosophy of 3a.

Dang, prior post did not exist when I started typing...

markngolf Loc: Bridgewater, NJ

I certainly understand your love of teaching. It would be dishonest to say I never had bad days, but 99% of my days were exciting and challenging. Loved the kids. Yes, there were a few PIA's, but few and far between. I still connect with quite a few on Facebook. Every Tuesday, 10 of my former colleagues and I have breakfast together. It's a blast - been going on for 22 years. Most of us have known each other for 45 - 55 years. Not too many secrets!
Mark

dancers Loc: melbourne.victoria, australia

these things caused me untold terror when I was a child. I could never understand them and still don't.

algebra was another form of torture for me as well.

thank goodness I have ever needed to understand them in adulthood~.

foodie65

Damn, another day passes and I haven't had to use algebra, geometry or calculus!!

dancers Loc: melbourne.victoria, australia

thankful for ALL mercies!

markngolf Loc: Bridgewater, NJ

Good job!!
Mark