Jenny has recently moved house and is working out her optimal commute. She can take an indirect route which involves taking a bus for 1 mile and then walk 0.75 miles. Or she can take a direct route and walk for 1.5 miles and this takes her 30 minutes. What is the most amount time that the bus journey can take for Jenny to be indifferent between the two routes assuming travel time is her only concern? Pick one
A) 5 minutes B) 10 minutes C) 15 minutes D) 20 minutes E) 25 minutes

Rationale: if jenny can walk 1.5 miles in 30 minutes , then she can talk 0.75 miles in half the time i . e . 15 minutes . for jenny to be indifferent between the two routes , the two journeys must have the same travel time . the direct route has a travel time of 30 minutes ( walking ) . the indirect route has a travel time of 15 minutes ( walking ) plus the bus journey . for the two routes to be the same the bus journey must take 15 minutes ( 30 - 15 ) . answer : c
Answer: C