A man travels $35$ km partly at $4$ $kmph$ and partly at $5$ $kmph$. If he covers the former distance at $5$ $kmph$ and the later distance at $4$ $kmph$, he could cover $2$ km more in the same time. The time taken to cover the whole distance at the original rate (in hours) is :
Answer is C
Case 1
$4t_{1}+5t_{2}=35$ ------(1)
Case 2
$5t_{1}+4t_{2}=37$ ------(2)
On solving simultaneous equations (1) and (2), we will get t1 = 5hrs and t2 = 3hrs
The time taken to cover the whole distance = t1+t2 = 5+3= 8 hrs