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Mathematics
Mathematics
Problem
The probability of drawing a science book from a shelf is
2
5
\frac{2}{5}
5
2
. If there are 18 science books, which of the following equations can be used to find
N
N
N
, the total number of books on the shelf? a)
N
18
=
2
5
\dfrac{N}{18}=\dfrac{2}{5}
18
N
=
5
2
b)
18
N
=
5
2
\dfrac{18}{N}=\dfrac{5}{2}
N
18
=
2
5
c)
18
N
=
2
5
\dfrac{18}{N}=\dfrac{2}{5}
N
18
=
5
2
d)
N
−
18
N
=
2
5
\dfrac{N-18}{N}=\dfrac{2}{5}
N
N
−
18
=
5
2
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