2 Gprep-Interesting DS

[Fiver]

Worth the time taken. Wanted to share with all.

[StudyGMAT]

I think the answers are E and C

[clock60]

for q2 my answer D
(1) first st obviously sufficient
(2) tricky one to me.. as no of friends sold the same number of tickets
the least number one could sold is 0
so the least number for second will be 1 it cannot be 0 as need different numbers and the least for third will be 2 the answer is yes (at least 2 for one) so D

[clock60]

my first solving was wrong too tricky the answer is E

let it be z total number of items
36x+(z-36)*(3/2)x=total
(1) 36x+(z-36)*1.5x=480
zx-12x=320 insufficient
(2) 36x+(z+2-36)*1.5x=510
zx-10z=340 insufficient
together
zx-12x=320
zx-10x=340
2x=20,x=10
z=44 as we have both unknowns we can solve total... (lazy to calculate)

but this is unfortunately not all...
again z is total number of items
fom bth statments
zx=480
(z+2)x=510
480/z=510/(z+2)
30z=960
z=32
as we have two answers 44 and 32 the answer is E

Study gmat and abhasjha thank you for solving!!
Fiver thanks for good question


36

[StudyGMAT]

This is how i solved it:

As per the two statements the cost of each (extra item) is $15. Now if the number of items is less than 36 than cost of producing each item = 15
Else = 10

As per these two possiblities, the number of items will be 32 or 44(as per clock60 calculation). Hence my answer will be E.

Please identify if I am wrong

[abhasjha]

IMO- E (for the first question )

Both 1) and 2) can result in two equations

1. 36 items * 10 dollars + y items * 15 dollars = 480

As from 2) we know that USD 30 more were generated by selling 2 more items, USD 15 was the price per item, hence the resulting values


2. x items * 15 dollars = USD 510

x items = 510/15 = 34. Hence for 34 items, a constant price of 15 dollars was charged.


Hence USD 15 can be the price for less than 36 items as well.

Therefore both 1) and 2) are INSUFFICIENT, hence E




ALTERNATIVELY :

36 or fewer: X per item
> 36: X per item for first 36 + 1.5X for each item over 36.

How many items last week?


For exactly 36 items, Bob would be paid $36*X. For, say, 40 items, Bob would be paid 36*X + 4*1.5*X. I don't know what X is.

(1) Last week, Bob was paid $480. Maybe he made one item and is paid 480 per item. Maybe he made two items and is paid 240 per item. ??? Not sufficient. Elim A and D.

(2) Bob made Y items last week and Y+2 items this week. Bob make $510 this week. Maybe Bob made 1 item last week and 3 this week, and was paid 170 per item. Maybe Bob made 3 items last week and 5 this week and was paid 102 per item. ??? Not suff. Elim B.

(1) + (2) Bob was paid 480 for Y items last week. Bob was paid 510 for Y+2 items this week. Y = 480. Y + 2 = 510. So two items added an additional $30, of $15 per item. But wait - is this the regular X rate, or the "overtime" 1.5X rate?

If it's the regular rate, then he produced 480/15 items last week, or 32 items. That's one possibility. If it's the 1.5X rate, then this week he produced some number of items at $15 per and $10 per. He had to have made at least 36 items at the $10 per rate (in order to get to the point of making $15 per item). So that's 36*10 = 360. He made 510 this week, so he still has another 150 to make, at 15 per. That's 10 items. So Bob made 36 + 10 = 46 this week. Then according to statement 2, he made 44 last week (46-2).

Two answers. Not sufficient. Elim C.
E is the answer.

[Fiver]

Great work all. Answers are E and D. Pretty tricky ones/

[finsisher]

question 2 was easy its D.. first one is lengthy haven't tried yet