patrick.net

Sounds more like a semantics problem than a Math problem.

Is it that mowerB 1.25 goes times as fast ? Like if Mower A can go 4 miles per hour mower B can go 5 miles per hour (4 x 1,25) ? Or is it that mowerB goes 9 miles per hour (4 +(4 x 1.25).

Awkward wording in my opinion, but if it said 1.25 times as fast, or 1.25 the speed, I would feel that I understood the question. Faster implies a difference to me, rather than just a factor.

42/1.25 = (33.60) 34 MowerB does the same job.

I enjoy math and logic problems... as well as trivia in general. One of my "dirty secrets" is that despite being a fairly decent engineer, I'm bad at math.. but good with spreadsheets.

Blue says

42/1.25 = (33.60) 34 MowerB does the same job.

I agree, but I think the catch is the term "faster"? If mower has a faster linear velocity (speed) but mows a smaller area (as measured in ft2 or similar) than the problem is indeterminate.

That said I agree with the awnser above. Context clues indicate the "fastness" of the mower is rated to how quickly it can clear a given square footage of terrain.

BayArea says

MowerB is 1.25x faster than mowerA

It takes 42 MowerA to cut a golf course in a given amount of time.

How many MowerB would it take to cut the same course in the same amount of time?

x*MowerB/1.00 = 42*MowerA/1.25

1.25x = 42*1.00
x = 42/1.25
x = 33.6

So the problem is unsolvable since you can't have a portion of MowerB's.

Also the term "faster" isn't defined. Does this mean it moves faster or it cuts a certain unit of grass 1.25x faster?

In problems like this I have always assumed that all characteristics are held the same unless otherwise stated, or unless changing one variable necessitates other factors change. So I would assume a doubling of speed (ie 2x faster) means a doubling of sq feet per minute of grass cut.

The "cant have 0.6 mowers" is a good detail to pick up on. I think the right answer is to probably round up to 34.

Context really matters though. If I was asked this question in an engineering interview, I would probably be more apt to think they expect me to ask many questions to check assumptions and think deeply about non-mentioned factors, vs if this was on a high school algebra quiz.

Some math teachers suck. Sometimes on a test I recall providing two answers due to issues like this, along with an explanation like "if X assumption then Y is the answer, else Z is the answer because..."
But a decent number of teachers would mark me wrong for not providing a singular answer. I always disagreed because the teacher is the one who evaluates the if/else statement, not me, so I don't see it as a way to cheat/game the test. Plus, at least IMO, it usually demonstrates more knowledge / critical thinking.