5 LB

[kpkanupriyakhmi]

Conference Ticket Advance Discounts
5-29 days in advance 15%
30-59 days in advance 30%
60-89 days in advance 40%

QHelen bought a ticket for $252. If she’d bought it 1 day later, she would have paid $306. How many days in
advance did she buy her ticket?
(A) 5
(B) 30
(C) 59
(D) 60
(E) 89
Didn't get the Q and the solution.

[n00bpron00bpron00b]

Consider this day table

89 days ago
88 days ago
.
.
62 days ago
61 days ago
60 days ago
59 days ago
58 days ago
.
31 days ago
30 days ago
29 days ago
.
.
6 days ago
5 days ago
.
.

Today

(read the table backwards from today to 89 days ago)

Let the original price of ticket be "x"
Halen bought the ticket at $252 (this is after some percent discount on the original price)
-> we do not know the amount of discount she got
-> as a result of which we also cannot determine how many days in advance did she book the ticket

3 cases now -

After, getting some percent discount on the original price (i.e. "x") the price became $252

case 1) If the ticket was bought 5-29 days in advance
Discount slab : 15% discount on the original price (i.e "x")
0.85 * x = 252
x = $296.47 -> This may be the original price

case 2) If the ticket was bought 30-59 days in advance
Discount slab: 30% discount on the original price ("x")
0.7 * x = 252
x = $360 -> This may be the orignal price

case 3) If the ticket was bought 60-89 days in advance
Discount slab: 40% discount on the original price ("x")
0.6 * x = 252
x = $ 420 -> This may be the original price

Now,

Important clue -

If she’d bought it 1 day later, she would have paid $306

There is a deviation in price

Let's eliminate choices

(A) 5 days in advance ? - This is out (refer day table at the top)
If she bought the ticket 5 days in advance her discount slab is 15%
One day later (that would be the 4th day) - price increases - but we have no discount slab for the 4th day (ends at 5 days ago)

(E) 89 days in advance ? - This is out
If she bought the ticket 89 days in advance
discount slab is 40%
One day later (that would be the 88th day) - price increases - but notice the 88th day lies under the same slab of 40% - the price of ticket remains constant

(C) Is out - Same reason as (E)

Remaining Choice (B) & Choice (D)

Choice (D) -
If she bought the ticket 60 days in advance
discount slab is 40%
If this is the case ; the original price of ticket will be $420 (refer case 3 above)
60 to 59 (a day increases)
=> discount slab changes from 40% to 30%
=> 30% discount on original cost price of $420
=> $294 => this is wrong (the question says 1 day later the price becomes $306)

Choice (B)
If she bought the ticket 30 days in advance her discount slab is 30%
If this is the case ; the original price of ticket will be $360 (refer case 2 above)
30 to 29 (a day increases)
=> discount slab changes from 30% to 15%
=> 15% discount on orginal cost price of $360
=> $306 - Ans !

all conditions are met
a) Cost price $360
b) 30% discount on $360 = $252 - The price she bought the ticket
c) If she buys the ticket 1 day later -> The cost price remains same $360 ; but instead of buying the ticket at $252 (30% discount on original price of $360) , she will be buying it at $306 (15% discount on the original price of $360)

I kept repeating the same mistake, took a while to realize - when you select a particular case ($296.47 or $360 or $420) as the original cost of the ticket - all subsequent calculations must be carried out with respect to that original price (this includes cases where there is transition in discount slabs)

[tommywallach]

Great and thorough explanation from Noob. Thanks, Noob.

By the way, I have to ask: why are you doing this? Why take so much time to answer so many questions so thoroughly? I must know!

-t

[kpkanupriyakhmi]

Will such Questions appear on the test?

[n00bpron00bpron00b]

By the way, I have to ask: why are you doing this? Why take so much time to answer so many questions so thoroughly? I must know!

Oh ! It's just that I find the learning/recalling process much better when the learning is done through forums/youtube tutorials, Q & A and E-learning platforms. I can barely maintain my concentration while reading books/long texts (something that I'll have to work upon for verbal :( )

[tommywallach]

Hey Kp,

I'll admit, this one seems like a LOT of work for a GRE question. I'd have to think that on the real test, it would be a bit simpler (maybe only two variation points to research, instead of a few). In any case, just make sure you understand the math/question in retrospect, and assume that on test day, you'd be unlikely to get a question like this one.

And Noob, that makes a lot of sense. I think you're right! And let me know if there's any way I can help you on the verbal side!

-t

[n00bpron00bpron00b]

Hi Tommy,

Yes, I'll soon be starting with verbal & will need your help for sure. BTW the new forum layout looks neat

[tommywallach]

Glad you like it. I'm still getting used...

-t