Interviewer view · keep this screen to yourself

1. Per store: a bubble tea shop in Singapore

You run the case. Read the prompt, answer questions from the notes below, and share data only when the candidate asks for it or gets stuck. Score at the end.

Case timer

00:00

Target length:

1. Read the prompt aloud

Read it slowly, then pause. Let the candidate ask questions before they structure.

A fictional bubble tea shop in Singapore sells 9,000 cups a month at SGD 5.50 each. Ingredients, cup and packaging cost SGD 1.60 per cup. Monthly fixed costs are rent SGD 12,000, staff SGD 14,000 and other costs SGD 3,000. Opening the shop cost SGD 150,000. Does one store make money, and how long does it take to pay back the opening cost?

2. Answers to clarifying questions

This case has no scripted clarifying answers. Answer from the prompt, and say "assume what you think is reasonable" if the prompt does not cover it.

3. A model structure

Compare the candidate's structure with this one. A different split can be just as good if it is clean and fits the problem.

Store profit = cups x contribution per cup minus fixed costs
- Contribution per cup
- Fixed costs per month
- Key: Breakeven cups and payback

4. The working, step by step

Each step shows how a strong candidate works it out. Share a new fact from it only when the candidate asks or is stuck, and let them do the math: the result in the dark box is what they should reach.

Step 1: Contribution per cup
What a strong candidate does: Price minus the variable cost of one cup.
Contribution per cup (SGD): 5.5 - 1.6 = 3.9
Step 2: Monthly contribution
What a strong candidate does: 9,000 cups at SGD 3.90.
Monthly contribution (SGD): 9,000 × 3.9 = 35,100
Step 3: Fixed costs
What a strong candidate does: Rent, staff and other costs.
Monthly fixed costs (SGD): 12,000 + 14,000 + 3,000 = 29,000
Step 4: Store profit
What a strong candidate does: Contribution minus fixed costs.
Monthly store profit (SGD): 35,100 - 29,000 = 6,100
Step 5: Breakeven volume
What a strong candidate does: Fixed costs divided by contribution per cup.
Breakeven cups per month: 29,000 ÷ 3.9 = 7,436
Step 6: Payback
What a strong candidate does: Opening cost divided by monthly profit.
Payback (months): 150,000 ÷ 6,100 = 24.59

The recommendation to listen for

At the end, say: "The CEO walks in. What is your recommendation?"

Yes, but only just. The store needs about 7,440 cups a month to break even and sells 9,000, a buffer of about 17 percent. Payback takes about 25 months. The biggest levers are cups per day (location) and rent. A 10 percent fall in volume would cut profit by more than half, because the fixed costs do not fall.

Score the candidate

Score each criterion from 1 to 5. A 2 or a 4 sits between the descriptions.

This case has no exhibit. Score Exhibit reading on how the candidate used the data you gave them: did they pick out the number that matters and say what it means?

Structuring

1: No clear structure, or a memorized framework that does not fit the problem.
3: A sensible structure, but with some overlap, a gap, or no clear priority.
5: A structure built for this problem, with no overlap and no gaps, a stated hypothesis, and a clear first step.

Math

1: Frequent errors, no units, or needed heavy help to finish.
3: Right answers but slow or messy working, or one error caught late.
5: Accurate and clearly narrated, with units, a sense check, and what the number means.

Exhibit reading

1: Read the chart aloud without finding the number that matters.
3: Found the key number but gave only part of the so-what.
5: Pulled the right number quickly and said what it means for the case.

Synthesis

1: Summarized what was done, with no clear answer.
3: Gave an answer, but with weak reasons or no next step.
5: Answer first, then two or three reasons with numbers, the main risk, and next steps.

Communication

1: Hard to follow: long silences, no signposting.
3: Clear most of the time, with some rambling.
5: Calm and concise, signposted each step, and checked in with the interviewer.

Total

0 out of 25

Score all five criteria to see the band and the feedback template.