Problem Solving

A frog lies on the floor of a 20 feet deep well, everyday it jumps 1 feet & falls down 1/2 feet, In how many days the frog will come out of the well

a 20
b 40
c 41
d 38
e 39

I also have a suggestion for Gabriel & beatthegmat here,
We have 2 sections under GMAT MATH i.e Problem Solving & Data sufficiency, Also a lot people giving the GMAT are 700+ aspirants, now I see many good problems in both these sections which can be considered as 700+ ability level, viz
some problems require u to know a concept, some involve extensive or higher order processing(big nos or small decimals/fractions), some are worded to be difficult to decode, some are naturally a little difficult etc, These problems however get lost between others in due course of time.

So IMO if there is another section under GMAT math like 700+ Problems or something, where we can promote problems from the existing sections which are deemed to be difficult in some sense by the moderators while their reviewing, I know that this would add some extra burden on the moderators, but it would be a boon for many people as it would serve as a ready reckoner for them to review good problems and learn/update their concepts.

Pls check if this is feasible.

The frog should cover 20 feet in 40 days. So on day 40 he will be on the edge of the well - he will need one more day to be out of the well so answer is 41 days.

Samir would appreciate if you could confirm.

PS - I completely agree it would help a great deal to have difficult problems under a different sub section.

sorry RI thats not correct, this isnt that simple as it seems

some how I am not surprised - I expected since u have put up the post it would have some twist :)

But i cant think of any thing else. Logically speaking i feet there must be some other way as the frog cant very well jump 1 feet straight and fall 1/2 feet and be hanging in mid air till he takes the next jump.

can u help me understand this - also can u share the source of the question?

I was solving OG 11 for the 1st time yesterday and some how the questions there seem simple compared to some of the ones I have seen on the forum. Can u share ur experience?

thanks so much

Well RI there is a little trick in this question,

The frog jumps 1 feet up & then falls down 0.5 feet in a day

(well its jumps along the walls so its falls down 0.5 on the wall & remains there, I think this is a little implicit)

so in a day effectivly it climbs .5 feet up

so for 20 feet it should take 20/05 i.e 40 days

but the twist is that it jumps 1 feet up & then falls 0.5 feet

so we can say that once the frog is 1 feet from the top of the well
the next jump it takes i.e. 1 feet up it will come out of the well & will not fall back

so we have : the frog will jump up 19 feet in 19 / 0.5 i.e 38 days

& on the 39 th day when its jump 1 feet up it will come out

Actually this question was asked to me by my friend who is also preparing for the gmat.

Ya agree with you that OG questions are a little simpler than some of them here but nowadays I've heard from a lot of people that GMAT maths is not that simple any more. So we need to be double sure from our side.

I've to review some Maths topics after which I would take up the OG.

hey
thanks a lot for the reply.

samirpandeyit62 wrote: I also have a suggestion for Gabriel & beatthegmat here,
We have 2 sections under GMAT MATH i.e Problem Solving & Data sufficiency, Also a lot people giving the GMAT are 700+ aspirants, now I see many good problems in both these sections which can be considered as 700+ ability level, viz
some problems require u to know a concept, some involve extensive or higher order processing(big nos or small decimals/fractions), some are worded to be difficult to decode, some are naturally a little difficult etc, These problems however get lost between others in due course of time.

So IMO if there is another section under GMAT math like 700+ Problems or something, where we can promote problems from the existing sections which are deemed to be difficult in some sense by the moderators while their reviewing, I know that this would add some extra burden on the moderators, but it would be a boon for many people as it would serve as a ready reckoner for them to review good problems and learn/update their concepts.

Pls check if this is feasible.

Well, if there are enuf people who want it, we could may be start a separate thread where 700+ questions are added,where both moderators and members could contribute ..
..but none of these are my decision to make... i would suggest u to PM ur suggestions to eric( beatthegmat) and wait for a response from him, he after all is the captain of the ship ..

regards..

Thanks Gabriel,
I'll move forward as per ur suggestion.