Hi there!

I see Gero already provided an approach to the calculations. 

What I would add, is that it's not only your accuracy of the numbers that they are testing. And it's by no means the things that they are most interested in. 

Instead, they rather care about how effective you are in explaining what you are doing with the numbers to another person. It simulates the interaction that you would have with a client on the same topic. 

So make sure that you take time to develop an approach and then explain it to the interviewer, seeking their feedback and integrating it. Then do the computations on your own, present them to the interviewer, and once they confirm the result, then interpret it.

Feel free to reach out and I can share a guide on this. 

And sharing here also an article on the most common terms that show up in interviews (for future interviews you might have):

https://www.preplounge.com/en/articles/what-typical-terms-show-up-in-case-study-interviews-for-consulting-firms

Best,
Cristian

Reading the responses from the coaches to this question gives me trust issues as a candidate who is looking to get coaching soon. The coaches all have their final answers as 306 but their methods/approaches lead to completely different answers. Some coaches did 19 * 7 to get to 306 while others 18 * 34 to get to 306. This might just be a typo, but the pattern across multiple answers makes me wonder if:

1. Coaches just rephrase other responses that are already posted.

2. Coaches don't really take the time to provide accurate responses to candidates who are really looking up to them for help and guidance.

3. Coaches validate incorrect responses from other coaches and do not pay close attention to the detail, hence the since xyz has already done abc response…

Please don't come after me, I am just posting my objective observation. 

The easiest way to answer a league question with each team playing the other twice, 1 home & 1 away, for someone who might get it in the future is to remember a very simple math equation. 

Total games = X(X-1) with X being the number of teams

In this case it would be: 18(18-1) = 18*17 = 306 games

Another real life example - The English Premier League

20 teams play the league in the same format mentioned in this question, so:

Total games in the EPL = 20(20-1) = 20*19 = 380 games

That being said, I have to commend Francesco who's response seems to be the most thought out and accurate.

Hi there,

Q: How would you calculate the correct number?

I would start first by defining the formula we need. The one I would recommend is the following:

• Number of games: Number of matches per day * Days with match

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Now let’s find the components:

• Number of matches per day: Total teams/2 = 18/2 = 9

(Logic: there are 2 teams needed for a match)

• Days with match: (Total teams – 1)*2 = 17*2 = 34

(Logic: each team will play against all the others, but not against itself, hence the -1, and they will play home and away, hence the *2)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Now let’s plug in the numbers:

• Number of games: Number of matches per day * Days with match = 9*34 = 306

Hope this helps,

Francesco

Hi there,

The trick with these questions is to simplify it as much as possible.

Most basic approach:

1. Each team plays once at home (against 17 opponents) and once away (again against the same 17), which totals 34 games per team.

2. There are 18 teams, so 18 x 34 leaves you with 306 total games.

Cheers,

Florian

Hi there,

Florian said it best (Gero overcomplicated a bit).

Remember, what they're looking for here is structure and organization. Rocketblocks is an excellent resource for practicing this type of math.