Answers ( 160 )
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    The legs of 4 horses: 4⋅4=16(legs)4⋅4=16(legs)

    The legs of  11 people: 11⋅2=22(legs)11⋅2=22(legs)

    The total legs: 16+22=38(legs)

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    Call Alice's age: a

            Betty's age: b

            Clara's age: c

        (a,b,c∈∈N*)

    According to the theme we have:
    a+b+c=29a+b+c=29(1)

    b−a=4⇒b=a+4b−a=4⇒b=a+4(2)

    c−b=6⇒c=b+6⇒c=a+4+6=a+10c−b=6⇒c=b+6⇒c=a+4+6=a+10(3)

    Change (2)(3) to (1) we have:
    (1)⇔a+b+c=29(1)⇔a+b+c=29

    a+a+4+a+10=29a+a+4+a+10=29

    3a+14=293a+14=29

    3a=29−14=153a=29−14=15

    a=5a=5(satisfy)

    Alice's age: 5 years old

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    We have : 3aa1 is divisible by 9

    <=> (3 + a + a + 1)  is divisible by 9

    <=> (2a + 4)  is divisible by 9

    <=>2(a + 2) is divisible by 9

    <=> a + 2 is divisible by 9

    <=> a = 7

    Answer 3771

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    a) 46;64

    b) We have:
    3=0+1+23=0+1+2

    6=1+2+36=1+2+3

    11=2+3+611=2+3+6

    ⇒6+11+20=37

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    a) 46;64

    b) We have:
    3=0+1+23=0+1+2

    6=1+2+36=1+2+3

    11=2+3+611=2+3+6

    ⇒6+11+20=37

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    Mai has notebooks number is :

                    3 + 4 = 7 (notebooks)

    James has notebooks is :

                    7 + 4 = 11 (notebooks)

                          Answer : 11 notebooks

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    Mai has notebooks number is :

                    3 + 4 = 7 (notebooks)

    James has notebooks is :

                    7 + 4 = 11 (notebooks)

                          Answer : 11 notebooks

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    Mai has notebooks number is :

                    3 + 4 = 7 (notebooks)

    James has notebooks is :

                    7 + 4 = 11 (notebooks)

                          Answer : 11 notebooks

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    There are 6 ways she can arrange them:

    Way 1: red, pink, yellow

    Way 2: red, yellow, pink

    Way 3: pink, red, yellow

    Way 4: pink, yellow, red

    Way 5: yellow, red, pink

    Way 6: yellow, pink, red

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    There are 6 ways she can arrange them:

    Way 1: red, pink, yellow

    Way 2: red, yellow, pink

    Way 3: pink, red, yellow

    Way 4: pink, yellow, red

    Way 5: yellow, red, pink

    Way 6: yellow, pink, red

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    Peter has the stamp number is:

              40 + 7 = 47 (stamps)

                 Answer : 47 stamps

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    Peter has the stamp number is:

              40 + 7 = 47 (stamps)

                 Answer : 47 stamps

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    Mai has the stamp number is:

             40 + 7 = 47 (stamps)

                    Answer : 47 stamps

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    There are 6 ways she can arrange them:

    Way 1: red, pink, yellow

    Way 2: red, yellow, pink

    Way 3: pink, red, yellow

    Way 4: pink, yellow, red

    Way 5: yellow, red, pink

    Way 6: yellow, pink, red

  • See question detail

    There are 6 ways she can arrange them:

    Way 1: red, pink, yellow

    Way 2: red, yellow, pink

    Way 3: pink, red, yellow

    Way 4: pink, yellow, red

    Way 5: yellow, red, pink

    Way 6: yellow, pink, red

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    To cut a wooden rod to 35 pieces, we must make 34 cuts.

    According to the problem, it takes 3 minutes to make 1 cut

    So: 3⋅34=102(minutes) to complete the cuts

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    To cut a wooden rod to 35 pieces, we must make 34 cuts.

    According to the problem, it takes 3 minutes to make 1 cut

    So: 3⋅34=102(minutes)3⋅34=102(minutes) to complete the cuts

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    The height of Paul:

     

    The height of rachel : 

              51 - 8 = 43 (inches)

                    Answer : 43 inches

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    \(\left(5\dfrac{1}{3}-2\dfrac{1}{2}\right)+\left(5\dfrac{1}{2}-3\dfrac{1}{3}\right)\)

    \(=5\dfrac{1}{3}-2\dfrac{1}{2}+5\dfrac{1}{2}-3\dfrac{1}{3}\)

    \(=5\dfrac{1}{3}-3\dfrac{1}{3}+5\dfrac{1}{2}-2\dfrac{1}{2}\)

    \(=2+3\)

    \(=5\)

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    We have : 3(2x - 1)2 + 7(3y + 5)2 = 0

    <=> 3(4x2 - 1) + 7(9y2 + 25) = 0

    <=> 12x2 - 3 + 63y2  + 175 = 0 

    <=> 12x2 + 63y2 + 172 = 0 

    <=> 12x2 + 63y2 = -172 (Meaningless)

    Because : 12x2 \(\ge0\) ; 63y2​ ​​ \(\ge0\)