1. The profit they will make

**Answer:** $\text{R31 447.80}$

**Explanation:**

Remember **Profit = Total Income - Total Expenses** - so, if they sell 340 units per week for 15 weeks at R12 each then:

\[\text{Total Income} = \text{Number of units per week} \times \text{Number of Weeks} \times \text{Price per unit}\]

Substituting gives:

\[\text{Total Income} = 340 \times 15 \times 12\]

So the Total income was $\text{R61 200.00}$

Now lets find out what the total expenses amounted to.

Total Expenses = Cost per unit x Total number of units + Cost per Week x Number of Weeks

Substituting gives:

\[\text{Total Expenses} = 4 \times 5100 + 623.48 \times 15\]

which is equal to $\text{R29 752.20}$

hence the profit will be $ \text{R61 200.00} - \text{R29 752.20} = \text{R31 447.80}$

2. The total cost for the event will be:

\[ \text{Total Cost} = \text{R12 000} + 285n\]

where $n$ is the number of Grade 12 learners.

SInce they managed to raise $\text{R31 447.80}$ this is a lot and can pay for the decor and $\text{R19 447.80}$ will be able to pay for $68$ learners.

3. Two facts of advice are:

(A) make sure your income is more than your costs;

(B) You can not have more than 68 learners at this event.