GMAT Math

Hello Everyone,

I am bit confused with this question (found on SHL test). I have passed the GMAT once but am thinking of retaking it again to improve my score in about a year. So atm, just practising with some random math stuff I find on internet to keep some reflexes.

Here's the question:


Can anyone help me out with this one? I have spent hours on this but I don't get it.

Thank you!

[spoiler]
The part average CO2 emission related to average occupancy is confusing.

Probably Wrong Approach
If I do the calculation without taking this into account, I get $11.5 (250*15*2*22-75*15*2*22)

If I take the average occupancy into account, I have :
Car average occupancy Cq = 1.433 (4.3*1/3)
Bike average occupancy Bq = 1.136 (1.6*.71)

Probably Right Approach but wrong answer
I divide the car CO2 emission by its average occupancy : 250*15*2*22/Cq
I divide the bike's emission by Bq : 75*15*2*22/Bq
Answer : $7.15

Probably Wrong Approach but right answer?
I multiply the car CO2 emission by its average occupancy : 250*15*2*22*Cq
I multiply the bike's emission by Bq : 75*15*2*22*Bq
Answer : $18

[/spoiler]

$100 a tonne should be converted to grams i,e ( 100/ (10^3 * 10^3 )

so it should be

( 250 * ( 1/10^4) * 15 * 22 ) - ( 75 * ( 1/10^4) * 15 * 22 ) =~ 50+ (not in any choice)

You cannot get 11.5 using your first method, its probably in 5 digits, Emission tax in seattle will be costlier than the cost of car

Other data in the table i find as distraction and isn't meaningful to this question ( My assumption: Tax will charged based on the Average Emission )

I am doing the conversion just before giving the answer in $ but I have not detailed the calculation.

He goes back and forth so he's travelling 30 km per day and not 15 km.

There's too much info and it is distracting. I don't understand how can someone do these type of questions in about 70 seconds. (average time in test : 39 questions/47 minutes).

I prefer the second approach but the answer is not in any choice.
For cars :
Average Occupancy (Cq) is 1.443
Average CO2 emission is 250 gram/person/km with an average occupancy of 1.443
So does that mean that Average CO2 emission is 250/1.443 gram/person/km (here average occupancy would be 1)?