taxi ride

[joanjgonzalez]

Hey guys, can anybody help me with this one?

The cost of a taxi ride is $1.20 for the first quarter mile and $0.40 for each succeding quarter mile. What is the cost in dollars for a taxi ride of m miles?

a. 1.20+1.60m
b. 0.80+1.60m
c. 0.80+0.40m
d. 1.60m-0.40
e. 1.60m-1.20

IMO is
[spoiler]b

Thanks![/spoiler]

[Brent@GMATPrepNow]

For me, the easiest way is to simply ignore the part about "$1.20 for the first quarter mile."

If we ignore this, we can see that it costs $1.60 for every mile (or 1.60m)
But of course, we can't just leave out that part.

Our answer so far of 1.60m doesn't take into account the fact that the first 1/4 mile costs more than the subsequent 1/4 miles.
How much more? $0.80 more.
So, we need to add that to our current total
We get 1.6m + 0.8 (B)

[mrsmarthi]

For me, the easiest way is to simply ignore the part about "$1.20 for the first quarter mile."

If we ignore this, we can see that it costs $1.60 for every mile (or 1.60m)
But of course, we can't just leave out that part.

Our answer so far of 1.60m doesn't take into account the fact that the first 1/4 mile costs more than the subsequent 1/4 miles.
How much more? $0.80 more.
So, we need to add that to our current total
We get 1.6m + 0.8 (B)

Tha't a cool way of solving the problem in shorter time. These are type of tricks we learn from Beat The GMAT. Thanks

[msd_2008]

I didn't understand how did you arrive at the $1.60 per mile figure. The question says that $1.20 for first quarter mile and $0.40 for each succeeding quarter mile......i think this means that 1.20x1 + 3x0.40 (because there are 3 more quarters in the one mile) = 1.20 + 1.20 = $2.40 per mile and hence for m miles it will be $2.40 m

Can you please correct my understanding?

Regards
MSD

[dmateer25]

It only costs 1.20 for the FIRST quarter mile.

Not for each first quarter mile of every succeeding mile.

[msd_2008]

Thanks Dmateer.....got it.

[msd_2008]

Thanks Dmateer.....got it.