Question

In a survey 27 percent of the people choose salad over a meat dish.In all 81 people chose salads.How many people were in the survey

Answer 1

this means that the 81 people who chose salad were also equivalent to 27% % of all the people surveyed (let's call them "x")

so:

81=27%x
or

81=$\frac{27}{100}$x

let's multiply both sides by 100:

8100=27x

and divide by 9:

900=3x

and by 3:
300=x

so we know that all the people surveyed numbered 300!