Hi, can anyone suggest a sound approach to solve this guesstimate question:
If a male and a female goat are put on a deserted island that has plenty of food and water on it, what would be the island’s goat population after ten years?
Thanks!
Guesstimate: Population question
Overview of answers
Upvotes
Best answer
Hi,
- Assume how much time it takes the population to double (let's say 2 years as they need 2 kids). So the population will double 5 times in 10 years
- Population in 10 years = 2*2^5
Best
Was this answer helpful?
Consider the following:
1. Given that you don't know how much time goat's pregnancy takes, knowing it is a mammal you should know it wouldn't be less than a couple of months, and probably not much more than 1 year. Assuming 1-2 (so an average of 1.5) pregnancy per a year per a female goat is fair.
2. We start with one female goat so year one is 1.5 *1, year to could be assumed as 1.5 * 2
(we round up the7.5 = .5 probability of having a female born times 1.5) and we add the number of males, which is always assumed to be the same num of females (so 2); total 2*1.5=3+2=5
3. Continue: 5+(1.5*2.5)+2.5..... n+(1.5* n/2)+n/2... 10+(1.5*5)+5
The number itself does not matter in this case, as long as you are not making an order of magnitude mistake. What matters is that your express explicitly your assumptions, flash out the model you are thinking of and reason through it. Good luck!
Check yourself:
Goat's pregnancy is indeed 5 months. Life expectation is 15-18 years (so irrelevant here).
https://articles.extension.org/pages/19720/goat-reproduction-puberty-and-sexual-maturity
Was this answer helpful?
Related Cases
Style:
Topics:
Ein Restaurantinhaber überlegt sich, Schulen mit Essen zu beliefern. Für seine Überlegungen würde er gerne wissen, wie viel Geld er verdienen würde, wenn er 1% der Schulkantinen-Mittagessen in Deutschland verkauft?
... (Open whole case)
5.4k
Times solved
Intermediate
Difficulty
Style:
Topics:
We are thinking of establishing a door-to-door distribution of an existing online newspaper in Kolkata, India. We haven't spent much time on how the process would work in practice yet. Can you help us evaluate the feasibility of the plan?
... (Open whole case)
4.5k
Times solved
Beginner
Difficulty
Expert case by Clara
Style:
Topics:
In an annual reunion with your MBA colleagues, one of them shares with you an idea of a new venture they have been working on: affordable baby strollers. They have deep experience in puericulture and childcare, and know there is a stable business to tackle.Given your experience in consulting, they a
... (Open whole case)
4.5k
Times solved
Intermediate
Difficulty
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
428
Meetings
11,839
Q&A Upvotes
127
Awards
186 Reviews