MKC Maths Murder Mystery

Maths

MURDER MYSTERY

MIDKENT COLLEGE

START

The Case

Professor William B Sutton PhD FRS was found dead in his manor house early Saturday morning under suspicious circumstances. Police are investigating and have established there were eight people in his house through Friday.These are the main suspects in the investigation. You are the lead investigator/s. Investigate each individual to learn more about their activities on the Friday and when they were in Prof Sutton’s house. The force have also been made aware of a dinner party that Prof Sutton held in the evening. Junior officers have been sent out to interview the guests and will let you know their findings as they get them.

Suspects

The Electrician

The Chef

The Hairdresser

The Business advisor and book illustrator

The Nurse and the physio

The Vet

Hairdresser 1

The technicians found these shredded parts of a picture in one of the bins. The sergeant is curious as to why it may have been ripped up. Put it back together in case there is a clue here.

• 5
• 4
• oui

Well done, it looks like this was the haircut the prof. wanted.

https://www.pinterest.co.uk/pin/539939442826610972/

RIGHT!

From interview we now know that the hairdresser was in the house from 11:00 to 12:00

Electrician 1

Eric the electrician was re-wiring Professor Sutton’s bathroom. The bathroom is rectangular: 8 metres by 4 metres and 3 metres tall.

Eric says he ran the electric cable along two adjacent sides of the room and then at a perpendicular angle from floor to ceiling on one side. How long would that make the cable?

15

Electricians work in mm, convert it.

15000|15,000

mm

Electrician 2

Eric completed the job and billed the Professor. We need to check it's correct. His rate is £250 per day, plus materials, plus VAT at 20%. Eric spent £175 on materials – though VAT is already included on these items. The job took two days. What should the bill have been?

775|£775|775.00|£775.00

Electrician 3

The sergeant wants to check whether Eric used a correct resistor. Ohm’s law tells us V=IR where V = Voltage in volts, I = Current in amperes and R = Resistance in ohms. The voltmeter measures the voltage at 180V and the ammeter measures the current at 12A. What should the resistance be?

15

ohms

RIGHT!

The electrician wrote down on his timesheet that he worked from 10:00 to 15:00. However, no one appears to be able to corroborate this.

Vet 1

The vet visited the house on the day in question as the professors' dog was unwell. The sergeant would like you to check the vet's work...

The dog weighs 1940g, convert this into kg for the next task

1.94|1.940

kg

Vet 2

The vet stated that he gave the dog a Methadyne Injection from Jurox (UK) Ltd. The doseage should be 0.8mg per kg of his body weight. Calculate exactly the dose that needs to be given to Benji in mg.

The dog weighs 1940g, what dosage of Methadyne should it have been given.

1.552

mg

Vet 3

mg is a unit of mass. To work out if the right amount is left over, we need to know the volume. The ratio is 5:1, volume to mass. The bottle supplied is 10ml.

What should the volume of the injection be?

7.76

ml

How much should be left in the bottle?

2.24

ml

RIGHT!

From interview we now know that the vet was in the house from 15:30 to 16:00

Chef 1

The sergeant is suspicious of a key part of the chef's desert and the proportions used. He has aquired the specific part of the recipe, but needs it scaled up.

Recipe, serves 8 100g white chocolate 30g mixed peel 300ml double cream 50g amaretti biscuits

For 20 g white chocolate g mixed peel ml double cream g amaretti biscuits

250

75

750

125

RIGHT!

From interview we now know that the chef was in the house from 15:00 to 22:00

Business & Book 1

The bank have provided details of the professors's finances. It 'appears' he gives a lot of his money to charity each month. The sergeant would like to know what percentage of the professor’s total spending goes to charity’.

Percentage of monthly spend that is charity

60%|60

Business & Book 2

The day before the murder, the professor met his business advisor and book illustrator. The plans of publishing the book were discussed. They were planning to sell 25 000 books of the 1st edition. The planned selling price was £19.99 per unit. 81% of the money received after sales was supposed to cover publishing expenses. How many pounds profit would be made?

£94952.50|94952.50|£94,952.50|94,952.50

RIGHT!

From interview we now know the book advisor & illustrator met the professor from 13:00 to 14:00. Of note, the housekeeper recalls the professor noticing a house key had gone missing around this time.

Nurse & Physio 1

Each day the Professor's heart rate is recorded, either by himself or the nurse. The sergeant wants this data in a chart. Drag the points to the correct positions.

✓ Check

Heartrate

Mon

Sun

Sat

Tues

Wed

Thurs

Fri

Nurse & Physio 2

Great, the chart looks brilliant. The serg now wants a bit of analysis. He would like to know the mean, median and mode of the data.

144.9

Mean

Give your answer to 1 decimal place

142

Median

140

Mode

Nurse & Physio 3

Perfect, finally to get a full picture of the professor's health. The sergeant would like to know his BMI. Use the formula and the information given to calculate it.

Weight = 91.5kg

Height = 170cm

BMI = Weight (kg) ÷ Height2 (m)

31.66

Give your answer to 2 decimal places

RIGHT!

From interview we now know that the nurse and physio were in the house from 09:00 to 09:45

Case closed!

3-5 correct

1-2 correct

0 correct

8-9 correct

10 correct

6-7 correct

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