On Field Street there are 9 houses in a row. At least one person lives in each house. Any neighboring houses together are inhabited by the most six people. What is the largest number of people that could be living on Field Street

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

it is contrapositive

i could not see the question too well so check yourself again too . this is because i want you to get it correct.