Apples' price consist a basic cost for a basic amount plus

Question

Apples' price consist a basic cost for a basic amount plus an additional cost for each pound thereafter. If 5 pounds apple cost $6, how much did 15 pounds cost?
1). Cost on 8 pounds is $1.5 more than that on 5 pounds. 
2). Cost on 10 pounds is $1 more than that on 8 pounds.

HIMALAYA · Answer

from i, Given that cost (5 lb) = $6.00 and we also know that the cost of 8 lb = cost (5 lb) + $1.5, we can answer the question.

From ii, its not possible.

So A.

remgeo · Answer

$6 = nx + (5-n)y
 where n is basic no of lbs
 x is amount for n no of lbs
 (5-n) is remaining lbs
 y is charge for remaining lbs. 

Using 1) $7.5 = nx + (8-n)y
 We can solve for y but not the remaining. 
Using 2) we cannot solve for n,x etc
Using both, again not possible. 

Hence E.

SunShine · Answer

Why not C.

from the question 5 p costs $6

From stat 1 8 p costs $7.5 (not sufficient)

From Stat2 10 p costs $8.5 ( not sufficient)

combining together,

8-5 =3 p costs $ 1.5
10-5 =5 p costs $2.5


there is a direct relation, the additional pound of apple costs $0.5 after the first 5 pound for $6.

so I would pick C.

old_dream_1976 · Answer

Your objective is to find y and that you can.
then just add 10y to the cost of 5 lb - to answer the question

Goreg · Answer

I would go with C too. 

Choosing A means that you take it as standard that the basic amount is 5 pounds and the basic price is 6$, which is not given by the stem.

The progression becomes obvious only after combining the two statements.

Goreg

remgeo · Answer

But the question says price consists a basic cost for a basic amount. But we dont know what that basic amount is. How can you assume that it is 5?

ywilfred · Answer

15 pounds cost = C = nx + (15-x)m ---(1)
n = basic cost
m = cost per pound thereafter
x = basic amount


We also know,

6 = nx + (5-x)m
So nx = 6 - (5-x)m

Subsitute this to (1), we have:

C = 6 - (5-x)m + (15-x)m = 6 - 5m + xm + 15m -xm = 6 - 10m

So we just need to solve for m.

From 1) we can solve for n as we can write the simultaneous equations:

6 = nx + (5-x)m -- (1)
7.5 = nx + (8-x)m -- (2)

Just take (2) - (1) and solve for m. 

(1) is sufficient.

From 2) Cost of 10 pounds apples is 1 dollar more than cost on 8 pounds apple.

We only know 

Cost on 8 pounds apple, A = nx + (8-x)m
Cost on 10 pounds apple, A+1 = nx + (10-x)m

Subtracting,

1 = 10m-xm-8m+xm = 2m
m = 1/2

Sufficient.

I go with D.

Apples' price consist a basic cost for a basic amount plus

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards