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GMATPrep- Division of company X
Source: Beat The GMAT — Data Sufficiency |
To calculate the service errors per 100 customers for division B we need
X: number of customers of division B
Y: number of service errors of division B.
St 1: combined service error rate for A and B = 1.5/100
(86+y)/(4850+x) = 1.5/100
We still have 2 unknowns---INSUFF
St 2: X = 9350
We still don't know anything about Y.---INSUFF
Combining 1 and 2
We can substitute x in the equation and solve for y. Since we can then determine all the unknown variables we can determine the service-error rate.
X: number of customers of division B
Y: number of service errors of division B.
St 1: combined service error rate for A and B = 1.5/100
(86+y)/(4850+x) = 1.5/100
We still have 2 unknowns---INSUFF
St 2: X = 9350
We still don't know anything about Y.---INSUFF
Combining 1 and 2
We can substitute x in the equation and solve for y. Since we can then determine all the unknown variables we can determine the service-error rate.
