Logitech 1

[logitech]

OA after discussion

[mals24]

Pick values
Let x = 1

Rakes not shipped
N = 1
D = 2
J = 3
F = 4
M = 4-1/2 = 3.5
A = 3.5-.5 = 3
M = 2.5
June = 2
July = 1.5
Aug = 1
S = 0.5
O = 0

M-O Total rakes unsold = 14
cost per month = 0.1
Total cost = 14*0.1 = 1.4

Answer C (1.4x)

[Brent@GMATPrepNow]

In the 4 months leading up to March, the company produces 4x rakes (x/month)
On March 1, x/2 rakes are shipped, leaving 3.5 x rakes for which the company must pay storage fees.
On April 1, x/2 rakes are shipped, leaving 3 x rakes for which the company must pay storage fees.
This continues until no rakes remain.

The total number of rakes for which storage fees are paid is 3.5x + 3x + 2.5x . . . +1x + 0.5x, which adds to 14x

The charge is $0.1/rake so the total fee is 1.4x

By the way, the sum 3.5 + 3 + 2.5 +. . . +1 + 0.5 can be found quickly by recognizing that this sum will be half the sum 7+6+5+...+2+1, which we can use a formula to determine.

[logitech]

OA 1.4X

[GMATters1001]

In March there were 3.5X rakes, in October there were 0 rakes. March-October is 8 months of rake storage. The average is (3.5-.5*3+3.5-.5*4)*X/2=1.75X (i.e. the average of the 4th and 5th number in a set of 8 evenly spaced numbers). Total rakes stored over that time = 1.75X*8 = 14X. At a rate of $.10 per rake that is $1.40X.

Answer is C

[GMATters1001]

Wow, I started typing my post before there was even a response, and then BAM!