Very difficult algebra word problems

Question

Hello Folks, I am stuck figuring out what the solutions are for these questions. Can someone please help me out with them? I would be very grateful!

1) The Acme Industrial Technical College has fallen on hard times. Last year its enrolment dropped by 20% and this year enrolment dropped another 15% from last year's. Next year the college expects to have 50% of this year's enrolment. What percentage of enrolment can be expected to drop for all 3 years? 2) Fifty white-tailed deer in a region are captured an ear-tagged, then released. Six months later, 50 more deer are captured, 35 of which are ear-tagged. Assuming the second group is representative of the deer population as a whole, what is the total population size ( rounded to the nearest integer )?

Abhishek009 · Answer

1. Year I - Enrollment be 100
Year 2 (Last Year) - Enrollment is 80 
Year 3 (This year) - Enrollment is 68
Year 4 - (Next Year) - Enrollment is 34

So, Percentage drop in enrollment is 66%

billionaire · Answer

Hello  RomeoPenheiro

These obviously are not GMAT official questions, the source is questionable and wording is funny.

I assume that I understood first question correctly, then it would be :

0.8 * 0.85* 0.5= 0.34

So the drop from first year to last is 66%, or 66% for 3 years.

Second one is probably just proportion if 50:35 is representative as population as a whole then :

50:35= x:65
35x= 3250
X=3250/35=92.8 ~ 93

RomeoPenheiro · Answer

billionaire  Thanks for the solutions. I got the questions from used GMAT prep materials that I bought.

For question 2, how did you get the equation 50:35= x:65? I don't understand how the 65 came to be!

Arro44 · Answer

Its is the 50 caught deer + the 15 deer which were caught and tagged earlier but are missing now.

RomeoPenheiro · Answer

But why are we considering the 15 deers that were caught earlier but are now missing?

billionaire · Answer

Hello again RomeoPenheiro What is the name of prep company that published that book, or source ? Do you have correct answers and explanations/solutions there ? What kind of prep company would not provide explanations to their questions ?

How 65 showed up ? Based on provided in question, we know there must be at least 65 white-tailed deer in existence, 50 of them ear-tagged and 15 not, so 50+15=65 If second group is representative of deer population as whole that means that proportion of 50:35 is equal to x:65, where x is real total population of deer and 65 is so far known population, that we have proof of.

Dlc930 · Answer

2) Fifty white-tailed deer in a region are captured an ear-tagged, then released. Six months later, 50 more deer are captured, 35 of which are ear-tagged. Assuming the second group is representative of the deer population as a whole, what is the total population size (rounded to the nearest integer)?

65

65

Bunuel · Answer

Please re-post in PS forum (here: problem-solving-ps-140/) according to the rules: rules-for-posting-please-read-this-before-posting-133935.html Thank you.

Very difficult algebra word problems

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