Answer:
The total cost for Mr. Smith's entire family can be calculated as follows:
\[ \text{Total Cost} = (\text{Number of Adults} \times \text{Adult Buffet Price}) + (\text{Number of Children} \times \text{Child Buffet Price}) \]
Let:
- \( x \) be the number of children.
- \( y \) be the price for the adult buffet.
- \( z \) be the price for the children's buffet.
- \( u \) be the percentage discount for senior citizens (if applicable).
The formula becomes:
\[ \text{Total Cost} = (2 \times y) + (x \times z) \]
This assumes that Mr. Smith, his wife, and his parents are all considered adults (hence the \(2 \times y\) for adults).
If there is a senior citizen discount (\( u \)), the formula for the total cost would be:
\[ \text{Total Cost with Senior Discount} = (2 \times y \times (1 - \frac{u}{100})) + (x \times z) \]
You would need specific values for \( x \), \( y \), \( z \), and \( u \) to calculate the exact total cost.
