Problem Solving

Hi All,

Company A has four different departments - Printing, Grooming, Offsetting and Distribution which together form the entire company A. The revenue earned from Printing was 60% of the company's total revenue in the month of January. In February however, the Printing department earned 20% more than in January. The revenue for the remaining department was same for both months. Approximately what percent of the company's revenue did the printing division earn for the month of February ?

A) 64%
B) 68%
C) 72%
D) 76%
E) 80%

OA C

However I got OA as A

below is how I did, can anyone explain what mistake I did,

For Jan,
TJ = PJ + GJ + OJ + DJ --- 1

TJ-PJ = GJ+OJ+DJ ---2

Since printing is 60 % of total revenue
PJ = 3/5 * TJ ------ 3

For Feb,
TB = PB + GJ + OJ + DJ ---4 (Since Grooming, Offsetting and Distributions remains same.)

PB = 120% PJ ==> PB = (120/100)*(3/5)*TJ ==> (18/25)TJ ----5

Substitute 2,3 and 5 in 4

TB = (18/25)TJ + TJ -(3/5)TJ

TB = (28/25)TJ ==> TJ = (25/28)TB --6

Substitute 6 in 5

PB = (18/25)*(25/28)TB ==> PB = (9/14) TB
Hence 64 %

But is wrong as per OA.

Can any one tell me what wrong I did ?

Thanks in advance.
Regards,
Uva.

TJ=PJ+GJ+OJ+DJ
TF=PF+GJ+OJ+DJ
TJ-PJ=TF-PF
(TJ-PJ)/(TF-PF)=1
On the other hand we have
PJ=60/100TJ,
substitute it in the equation,so we have:
TJ=(25/28)TF, and PJ=60/100TJ,therefore TJ=50/36PF,so we have:
PF=64%TF
so the answer is 64%

[email protected] wrote:Hi Uva@90,

Your answer is correct. What is the source of this question? It's possible that the OA is a typo.

GMAT assassins aren't born, they're made,
Rich

Thanks Rich,

This Question is from "Crack Verbal".

Regards,
Uva.

Uva@90 wrote:Hi All,

Company A has four different departments - Printing, Grooming, Offsetting and Distribution which together form the entire company A. The revenue earned from Printing was 60% of the company's total revenue in the month of January. In February however, the Printing department earned 20% more than in January. The revenue for the remaining department was same for both months. Approximately what percent of the company's revenue did the printing division earn for the month of February ?

A) 64%
B) 68%
C) 72%
D) 76%
E) 80%

OA C

However I got OA as A

below is how I did, can anyone explain what mistake I did,

For Jan,
TJ = PJ + GJ + OJ + DJ --- 1

TJ-PJ = GJ+OJ+DJ ---2

Since printing is 60 % of total revenue
PJ = 3/5 * TJ ------ 3

For Feb,
TB = PB + GJ + OJ + DJ ---4 (Since Grooming, Offsetting and Distributions remains same.)

PB = 120% PJ ==> PB = (120/100)*(3/5)*TJ ==> (18/25)TJ ----5

Substitute 2,3 and 5 in 4

TB = (18/25)TJ + TJ -(3/5)TJ

TB = (28/25)TJ ==> TJ = (25/28)TB --6

Substitute 6 in 5

PB = (18/25)*(25/28)TB ==> PB = (9/14) TB
Hence 64 %

But is wrong as per OA.

Can any one tell me what wrong I did ?

Thanks in advance.
Regards,
Uva.

Alternative approach:
assume that the revenue earned from Printing was $60 and total revenue was $100 for January

Jan total revenue = revenue from printing + other departments
100 = 60 + 40

Feb. printing revenue = 1.2 * 60 = $72
Feb total revenue = 72 + 40 = 112

72/112 = 9/14 = 7/14 + 2/14 = 0.5 + 1/7 = 0.5 + 0.14 = 0.64 =>64%