2025 NASS PRELIMS P1 Q23

A shop sells chocolate (C), lemon (L) and vanilla (V) cakes. In July, it sold 120 chocolate, 80 lemon and 100 vanilla cakes. Chocolate cakes cost SGD 5 and sell for SGD 8; lemon cakes cost SGD 4 and sell for SGD 7; vanilla cakes cost SGD 6 and sell for SGD 9.

1. Represent the cost and selling prices in a \(2\times3\) matrix \(P\), with columns C, L and V and rows Cost Price and Sell Price.[1]
2. Find \(T=P\begin{pmatrix}120\\80\\100\end{pmatrix}\).[2]
3. State what each element of \(T\) represents.[1]
4. The element of \(V\), where \(V=QT\), represents the shop’s profit. Write down \(Q\).[1]