SOLUTION: Mr. Smith waters one of his plants every 10 days and another plant every 14 days. If he waters both plants today, when is the next time both plants will be watered on the same day

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Question 1163911: Mr. Smith waters one of his plants every 10 days and another plant every 14 days. If he waters both plants today, when is the next time both plants will be watered on the same day?
Answer by greenestamps(13198) About Me  (Show Source):
You can put this solution on YOUR website!


The number of days to the next time both plants are watered on the same day is the least common multiple (LCM) of 10 and 14.

There are numerous ways to find the LCM of two integers. Here is the one I like best:

(1) Make a fraction from the two integers: 10%2F14
(2) Simplify as far as possible: 10%2F14+=+5%2F7
(3) Cross multiply in either direction to get the LCM: 14%2A5=70, or 10%2A7=70

ANSWER: The plants will again be watered on the same day 70 days from now.

Note you can get some good mental exercise by solving the problem informally.

The LCM has to be a multiple of 10; since the other number 14 is even, you can get the LCM by multiplying by 5: 14*5 = 70.