Answer: We can calculate the size of the lot in acres and then compare it to the minimum size of 3/4 of an acre that the family is looking for.
1 acre = 43,560 square feet
So, a 30,000 sq-ft lot is equivalent to:
30,000 sq-ft / 43,560 sq-ft/acre = 0.6864 acres
Since 0.6864 acres is less than 3/4 of an acre, the family's agent will be wasting her time by showing them the house with a 30,000 sq-ft lot. The lot is not big enough for the family's needs.
Explanation: