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If a , b , and c are consecutive odd integers, which express
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09 Nov 2017, 07:16
09 Nov 2017, 07:16
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If a, b, and c are consecutive odd integers, which expression must be odd?
Choose \(all\) that apply.
❑ \(a*(b+c)\)
❑ \((a+b) - c\)
❑ \(a*b*c\)
❑ \(2*(c-a) + b\)
❑ \(a + b + c\)
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Official Answer
B,C,D,E
Re: If a , b , and c are consecutive odd integers, which express
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09 Nov 2017, 08:30
09 Nov 2017, 08:30
1
Let's check them one by one
❑ \(a*(b+c)\) -> odd+odd = even, odd*even = even, so it must be even
❑ \((a+b) - c\) -> odd+odd = odd, odd-odd = odd, so it must be odd
❑ \(a*b*c\) -> odd*odd = odd, so it must be odd
❑ \(2*(c-a) + b\) -> odd-odd = odd, even*odd = even, even+odd = odd, so it must be odd
❑ \(a + b + c\) -> odd+odd = even, even+odd = odd, so it must be odd
Then, the answers are B, C, D, E.
❑ \(a*(b+c)\) -> odd+odd = even, odd*even = even, so it must be even
❑ \((a+b) - c\) -> odd+odd = odd, odd-odd = odd, so it must be odd
❑ \(a*b*c\) -> odd*odd = odd, so it must be odd
❑ \(2*(c-a) + b\) -> odd-odd = odd, even*odd = even, even+odd = odd, so it must be odd
❑ \(a + b + c\) -> odd+odd = even, even+odd = odd, so it must be odd
Then, the answers are B, C, D, E.
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Re: If a , b , and c are consecutive odd integers, which express
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22 Jan 2019, 07:13
22 Jan 2019, 07:13
1
Carcass wrote:
If a, b, and c are consecutive odd integers, which expression must be odd?
Choose \(all\) that apply.
A) \(a*(b+c)\)
B) \((a+b) - c\)
C) \(a*b*c\)
D) \(2*(c-a) + b\)
E) \(a + b + c\)
To solve this question, we can EITHER apply the rules for ODDS and EVENS (as IlCreatore has done) or we can plug in 3 consecutive ODD integers for a, b and c
How about a = 1, b = 3 and c = 3
We get:
A) \(1*(3+5) = 8\), which is EVEN. ELIMINATE.
B) \((1+3) - 5 = -1\), which is ODD. KEEP!
C) \(1*3*5 = 15\), which is ODD. KEEP!
D) \(2*(5-1) + 3 = 11\), which is ODD. KEEP!
E) \(1 + 3 + 5 = 9\), which is ODD. KEEP!
Answer: B, C, D, E
Cheers,
Brent
