A number line with the middle number being 64 and a bolded line headed to the left, open circle on 64
27 prime factors: 9*3 prime factors of 9: 3*3
117 prime factors: 39*3 prime factors of 39: 13*3
that would make 3 the greatest common factor. for the other ones break down the numbers into the smallest amount and see which largest factor both numbers have in common.
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1 mile = 5280 feet
81 * 5280 = 427680 feet per hour
1 hour = 3600 seconds
427680 / 3600 = 118.8 feet per second
118.8 * 15 = 1782 feet in 15 seconds
