For part (a) of the question, we are asked to select two of the number cards in a way that their sum forms a whole number. Let's analyze the numbers:

The number cards are:

• 4.5
• 7.02
• 0.6
• 0.98

(a) Solution:

To make a whole number, the decimal parts of the numbers must add up to 1 (or multiples of 1).

• $4.5 + 0.5 = 5$ (whole number) Therefore, $4.5 + 0.5 = 4.5 + 0.98$ gives a whole number $5.48$, which is wrong.

The correct combination might