Final Answer:
The correct expression for (15 + 30) as a multiple of a sum of whole numbers with no common factor is c. 5 × (3 + 6).
Step-by-step explanation:
Analyze the options:
a. 2 × (7.5 + 15): Both 7.5 and 15 have a common factor of 1.5, violating the condition of no common factor.
b. 3 × (5 + 10): Both 5 and 10 have a common factor of 5, violating the condition.
c. 5 × (3 + 6): Both 3 and 6 are prime numbers and therefore have no common factor. This satisfies the condition.
d. 15 × (1 + 2): 15 itself has a common factor of 3, violating the condition.
Therefore, c. 5 × (3 + 6) is the only option that expresses (15 + 30) as a multiple of a sum of whole numbers with no common factor.
The expression 5 × (3 + 6) translates to:
5 × 9: This clearly shows that 15 + 30 can be expressed as a multiple of a sum of whole numbers (3 + 6) with no common factor (both 3 and 6 are prime).