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# Maths

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79
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+120

2)How many numbers among 1, 2, 3,  1000 are not divisible by 9?

3)Andrew chooses a number from 1 to 100, and Mary also chooses a number from 1 to 100. (They may choose the same number.) It turns out that the product of their numbers is even. In how many ways could Andrew and Mary have chosen their numbers?

4)How many numbers between 50 and 250 (inclusive) are not perfect squares?

5)Dmitri has a pair of standard dice; one die is blue, and the other die is yellow. He rolls both of his dice. How many ways could the number on the blue die be larger than the number on the yellow die?

6) Bob flips a penny, a nickel, and a dime. How many ways can she get at least two heads?

wiskdls  Apr 15, 2018
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#1
+92215
+2

3)

Outcomes of equal chance

Even even

Even odd

Odd even

Odd odd

Only the 2 odds wont multiple to an even so that's 3/4 chance that the product will be even.

No of ways = 100×100-50×50 = 7500

Melody  Apr 15, 2018

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