To calculate how many houses are needed, we can set up the following equation:
6 groups of 7 = 3 groups of 14 = 42 people total
Let x be the number of houses needed.
Then, 6x = 3(2x) = 42
Solving for x:
6x = 42
x = 42 / 6
x = 7
So, 7 houses are needed to accommodate six groups of seven, which is equivalent to three groups of 14, totaling 42 people.