How much does a watch lose per day, if its hands coincide every 64 minutes?
32$ \dfrac{8}{11} $min.
36$ \dfrac{5}{11} $min.
90 min.
96 min.
Explanation:
60 min. spaces are covered in$ \left(\dfrac{60}{55} \times 60\right) $min.= 65$ \dfrac{5}{11} $min.
Loss in 64 min. =$ \left(65\dfrac{5}{11} - 64\right) $=$ \dfrac{16}{11} $min.
Loss in 24 hrs =$ \left(\dfrac{16}{11} \times\dfrac{1}{64} \times 24 \times 60\right) $min.=32$ \dfrac{8}{11} $min.