Tim has a scale model of an airplane which says it is in a 1: 15 ratio what shoes that mean?

How many of the 250 grandparents in the population would you expect to prefer online shopping with merchant a? merchant a: 4 merchant b: 6 merchant c: 2 merchant d: 3 other: 5 none: 5 answer choices: a.about 4 b.about 8 c.about 40 d.about 21

The sum of the reciprocal of a positive number and the reciprocal of 2 more than the number is 3/4 equation: the number is

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?