Source: MGMAT
Bob bikes to school every day at a steady rate of x miles per hour. On a particular day, Bob had a flat tire exactly halfway to school. He immediately started walking to school at a steady pace of y miles per hour. He arrived at school exactly t hours after leaving his home. How many miles is it from the school to Bob's home?
(x + y) / t
2(x + t) / xy
2xyt / (x + y)
2(x + y + t) / xy
x(y + t) + y(x + t)
I want to know what is wrong with my method below:
[spoiler]Let d be the total distance from home to school.
(d/2x) + (d/2y) = (d/x) + t
Which gives d = (2xyt)/x-y[/spoiler]
That is nowhere in the question, OA however is the very similiar C.
Can anyone please point out my error?
Bob bikes to school every day at a steady rate of x miles per hour. On a particular day, Bob had a flat tire exactly halfway to school. He immediately started walking to school at a steady pace of y miles per hour. He arrived at school exactly t hours after leaving his home. How many miles is it from the school to Bob's home?
(x + y) / t
2(x + t) / xy
2xyt / (x + y)
2(x + y + t) / xy
x(y + t) + y(x + t)
I want to know what is wrong with my method below:
[spoiler]Let d be the total distance from home to school.
(d/2x) + (d/2y) = (d/x) + t
Which gives d = (2xyt)/x-y[/spoiler]
That is nowhere in the question, OA however is the very similiar C.
Can anyone please point out my error?


















