Question

Chinki can cycle from point $A$ to point $B$ and return to point $A$ in $10$ minutes. She can cycle there and walk back in $20$ minutes. It will take _____ mins for her to walk there and walk back.

• A. $10$
• B. $20$
• C. $30$
• D. $40$

Answer 1

Answer: (C)

$30$

Total time taken to cycle from $A$ to $B$ and $B$ to $A=10$ minutes
$\therefore$ Time taken to cycle from $A$ to $B=5$ minutes
Total time taken to cycle from $A$ to $B$ and to walk back from $B$ to $A=20minutes$
i.e. $5+$ Time taken to walk from $B$ to $A=20$
$\Rightarrow$ Time taken to walk from $B$ to $A=20-5=15minutes$
$\therefore$ Total time taken to walk from $A$ to $B$ and to walk back from $B$ to $A=15+15=30mins$.