Need to come up with a Math Brain Teaser in the next 1/2 hour and can't find one! anyone have one to share????

A plane maintains an average speed of 225mph from London to New York. It then returns from New York to London at an average speed of 180mph. What is the average speed for the entire journey?




200mph: if the one-way distance was 1000 miles (for example), the outward journey took 1000/225 hours and the return journey took 1000/180 hours. Therefore the total time taken was (1000/225 + 1000/180) hours for 2000 miles. So the average speed was 2000 / (1000/225 + 1000/180) which equals 200mph. The answer remains the same if you change the distance to any number of miles.

The son of a rich bullion merchant left home on the death of his father. All he had with him was a gold chain that consisted of 119 links. He rented a place in the city center with a shop at the lower level and an apartment at the upper level. He was required to pay every week one link of the gold chain as rent for the place.

The landlady told him that she wanted one link of the gold chain at the end of one week, two gold links at the end of two weeks, three gold links at the end of three weeks and so on.

The son realized that he had to cut the links of the gold chain to pay the weekly rent. If the son wished to rent the place for 119 weeks, what would be the minimum number of links he would need to cut?

what's the answer AMN?

Here's one......One woman with MS.....and her calculator has decided to stop working. Should she assume she has $$ because she still has checks in her checkbook?

My eyes glazed over before I got through reading the problem.....I'm no good at math.

4!

Sorry, she didn't ask for the answer, just the question, then I had to take a nap! The minimum number of cuts needed to be made is 4 for a chain with 119 links. If the links are numbered serially from 1 to 119, then the cuts would be made on the following links: 6, 17, 38, and 79.

Start paying with the cut links, 1+1+1+1, at the end of the fifth week, the 5-link piece is given and the 4 one-link pieces are taken back; at the end of the tenth week, the 10-link piece is given and the 4 one-link pieces as well as the 5-link piece are taken back, and so on.

My poor MS cogfoggy mind cannot wrap itself around this. How do you people manage to do this??? I've read it over and over and just cannot grasp it.

I'm a dummy........

It's a lot like using coins, Kell; you're not a dummy, just ask dm!

Oh my, I don't like word problems... I like math, but I'm no expert, lol.