Problem Solving

Hi All,

We're told that a certain taxi company charges $3.10 for the first 1/5 of a mile plus $0.40 for each additional 1/5 of a mile. We're asked for the total charge for a taxi ride that was 8 miles long?

The prompt gives us the price per 1/5 of a mile for a taxi ride. It's worth noting that once you travel the first 1/5 of a mile, the price for each additional 1/5 mile is $0.40 - and two pairs of answers choices differ by $0.40, so you have to be careful to make sure that you don't accidentally include (or ignore) one of the $0.40 increments...

An 8-mile trip is FORTY 1/5-mile increments:
the 1st is $3.10
the remaining 39 are $0.40 each

$3.10 + (39)($0.40) =
$3.10 + $15.60 =
$18.70

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

swerve wrote:A certain taxi company charges $3.10 for the first 1/5 of a mile plus $0.40 for each additional 1/5 of a mile. What would this company charge for a taxi ride that was 8 miles long?

A. 15.60
B. 16.00
C. 17.50
D. 18.70
E. 19.10

The OA is D

Source: GMAT Prep

We know that for the first 1/5 mile of the 8-mile trip, the taxi company charges $3.10. For the next 7 4/5 miles, each 1/5 of a mile will cost $0.40. We need to find out how many 1/5s are in 7 4/5.

Since 7 4/5 = 39/5, there are 39 1/5s in 7 4/5. Therefore, the total cost of the 8-mile trip would be:

$3.10 + 39($0.40)

$3.10 + $15.60

$18.70

Answer: D

swerve wrote: ↑

Tue Feb 19, 2019 8:42 am

A certain taxi company charges $3.10 for the first 1/5 of a mile plus $0.40 for each additional 1/5 of a mile. What would this company charge for a taxi ride that was 8 miles long?

A. 15.60
B. 16.00
C. 17.50
D. 18.70
E. 19.10

The OA is D

Source: GMAT Prep

In other words, the taxi company charges $3.10 for the first 0.2 miles PLUS $0.40 for each additional 0.2 miles.

Let's think of the 8-mile taxi ride in two parts:
Part I) The first 0.2 miles
Part II) The remaining 7.8 miles

Part I: The first 0.2 miles costs $3.10

Part II: 7.8 ÷ 0.2 = 39 0.2-mile increments.
So, the total cost of those 39 increments = (39)($0.40) = $15.60

So, the total cost of the entire trip = $3.10 + $15.60 = $18.70

Answer: D