9+1 is 10. So 180/10 is 18. There are 18 groups of 9 white sheep, and 18 groups of 1 black sheep.
There are 162 white sheep
There are 18 black sheep
A complete set of sheep is 9 whites + 1 black = 10 sheep.
How many sets of 10 in 180 ? Looks like 18 sets.
In 18 sets you have 18 black and 18 x 9 = 162 white.
There are 162 white sheep and 18 black sheep in the flock. The ratio is 9 white sheep for every 1 black sheep. This results in a total of 180 sheep in the flock.
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