A question came up recently on a GMAT forum:
"A ranch has both horses and ponies. Exactly 5/6 of the ponies have horsehoes, and 2/3 of the ponies with horseshoes are Icelandic. If there are 3 more horses than ponies, what is the minimum number of horses and ponies combined on the ranch?"
A question like this can be tough to conceptualize, but sometimes a picture really is worth 1000 words. So here is a visual aid that you can use to understand questions like this in the future:
I hope this helps a little. Organizing it this way, you can see that the number of ponies must be a number divisible by 6 and again by 3 -- in other words, a number you can divide by 6 and then take that result and divide it by 3. So the minimum number would be 18. Then if there are 3 more horses than ponies, there must be 21 horses. That makes the minimum number of horses/ponies to be 39 total.
If you don't see why the number of horses must be divisible by 6 and then by 3, just try inserting a number that's not divisible by 6 into that place in the flowchart and you'll see that you end up with non integer values for the horses and ponies. You can't have half a pony any more than you can have half a bunny! :)
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