There are 25 sheep, 50 cows and 100 horses on a farm. Amy says that the ratio of sheep to cows to horses is 25:50:100, Ann says that the ratio should be 5:10:20, and Alan 1:2:4. Who is right?

There are 25 sheep, 50 cows and 100 horses, so the ratio could be 25:50:100.

25:50:100 = (25 ÷ 5) : (50 ÷ 5) : (100 ÷ 5) = 5:10:20

25:50:100 = (25 ÷ 25) : (50 ÷ 25) : (100 ÷ 25) = 1:2:4

So, 5:10:20 and 1:2:4 are equivalent to 25:50:100.

Thus, three of them, are right.