Question

The ratio of an object's weight on Earth to its weight on Neptune is 5 : 7. How much would a person who weighs 150 pounds on Earth weigh on Neptune?. A) 107 1/7 pounds. B) 170 pounds. C) 210 pounds. D) 750 pounds

Answer 1

The ratio of an object's weight on Earth to its weight on Neptune is 5 : 7
So,
We can use proportions to find out the weight of a person on Neptune.
Lets start:
E refers to Earth
N refers to Neptune

Therefore,
E:N = 5:7
Converting them into fractions:
E/N = 5/7
Substituting the value of weight on earth.
150/N = 5/7
Solving for N.
5 N = 150 x 7
5 N = 1050
N = 1050/5
N = 210 pounds.

Hence,the right answer is option : 
C) 210 pounds.

Answer 2

5/7 = 150/x
5x = 1050
x = 1050/5
x = 210 lbs <===