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Mathematics
Problem
Total number of values of
x
x
x
, of the form
1
n
\frac{1}{n}
n
1
,
n
∈
N
n \in N
n
∈
N
in the interval
x
∈
[
1
25
,
1
10
]
x \in \left[\frac{1}{25}, \frac{1}{10}\right]
x
∈
[
25
1
,
10
1
]
, which satisfy the equation
{
x
}
+
{
2
x
}
+
⋯
+
{
12
x
}
=
78
x
\{x\} + \{2x\} + \dots + \{12x\} = 78x
{
x
}
+
{
2
x
}
+
⋯
+
{
12
x
}
=
78
x
(where
{
⋅
}
\{\cdot\}
{
⋅
}
represents fractional part function), is a. 12 b. 13 c. 14 d. 15
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