Kimberly77
BrentGMATPrepNow
Bunuel
A delivery truck starts on its route with a load of goods weighing T tons. At each of its first 4 stops, 1/2 of the weight of the goods still on the truck is unloaded. After the 4th stop, what is the weight, in tons, of the goods still on the truck?
A. 15T/16
B. T/4
C. T/6
D. T/8
E. T/16
PS21183
If half the weight is REMOVED, then half the weight REMAINS
Initially, weight = T (tons)
After 1 stop: weight remaining = (1/2)T
After 2 stops: weight remaining = (1/2)(1/2)T
After 3 stops: weight remaining = (1/2)(1/2)(1/2)T
After 4 stops: weight remaining = (1/2)(1/2)(1/2)(1/2)T = (1/16)T = T/16
Answer: E
Cheers,
Brent
Hi
BrentGMATPrepNow, when using number 20 testing, I end up with 20> 10> 5 > 2.5> 1.25/20 ?
Wondering why it only work with 16 only? Could you help? Thanks
I believe you are using the input-output approach.
Am I right?
If so, you can use ANY values you want.
If T =
20 (tons), then the answer to our question is
1.25 tons of goods remaining (NOT 1.25/20) .
So now we'll take each answer choice, and INPUT T =
20, to see if we get an OUTPUT of
1.25If you do this, you will see that none of the first four options work, but...
E) T/16 =
20/16 =
1.25. Perfect!!