A) 20
B) 25
C) 12
D) 24
E) 50
Correct Answer: B
Solution :
Let total number of stones be \[=2n+1\] Total travelled distance \[2\left\{ 2\times 10\frac{(n-1)n}{2}+10n \right\}+10n\] But total travelled distance\[=3000\text{ }m\] \[\therefore \]\[10(2{{n}^{2}}+n)=3000\] \[\Rightarrow \] \[2{{n}^{2}}+n-300=0\] \[\Rightarrow \] \[n=12\] \[\therefore \]Total number of stones is 25.You need to login to perform this action.
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