Fraction - Problem Solving

Question

there are 50 black sheep and 42 white sheep in a paddock. How many black sheep must be removed so that 1/3 of the remaining sheep are black

Answer 1

There are 50 black sheep, 42 white sheep, 92 total sheep total

If the number of black sheep removed is b, then the number of black remaining is:

50 - b

And the total number of sheep remaining is:

92 - b

The remaining ratio of black sheep to total sheep is 1/3 so:

(50 - b) / (92 - b) = 1/3

92 - b = 3(50 - b)

92 – b = 150 - 3b

2b = 58

b = 29

Answer 2

(50-x)/(92-x) = 1/3

x=# of black sheep removed

50-x=# of black sheep left

92-x=total # of sheep left