78. A manufacture produced x percent more video cameras in 1994 than in 1993 and y
percent more video cameras in 1995 than in 1994. If the manufacturer produced 1,000
video cameras in 1993, how many video cameras did the manufacturer produce in 1995?
1). xy=20
2). x+y+xy/100 = 9.2
ans is[spoiler] b[/spoiler
gmat prep - q ..cant figure out...thanks
Camera's
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No useful info. x = 2%, y = 10%, or x = 4%, y = 5%deltaforce wrote:78. A manufacture produced x percent more video cameras in 1994 than in 1993 and y
percent more video cameras in 1995 than in 1994. If the manufacturer produced 1,000
video cameras in 1993, how many video cameras did the manufacturer produce in 1995?
1). xy=20
1000 * (1 + x/100)(1 + y/100) = 1000 (1 + y/100 + x/100 + x*y/10,000) = 10 * (100 + x + y + x*y/100)2). x+y+xy/100 = 9.2
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Let's call
C94 = number of cameras produced in 94
A manufacture produced x percent more video cameras in 1994 than in 1993 so C94 = (1+x/100)C93
y percent more video cameras in 1995 than in 1994
so C95 = (1+y/100)C94 ---> C95 = (1+y/100)(1+x/100)C93
you are given the value of C93, so in order to calculate the value of C95 you need to know (1+y/100)(1+x/100)
use FOIL in that expression
(1+y/100)(1+x/100) = 1 + (yx/10000) + y/100 + x/100 (1)
with this information take a look at the statements
statement I
xy=20
can you know the value of the expression just with that information? no
insufficient
statement II
compare the two expressions
x+y+xy/100 = 9.2
1 + (yx/10000) + y/100 + x/100
can you transform the first expression to get the second one?
divide everything by 100
x/100 + y/100 + xy/10000 = 9.2/100
sum 1 to both sides
if you compare now the both expressions
1 + (yx/10000) + y/100 + x/100
1 + x/100 + y/100 + xy/10000 = 1 + 9.2/100
you see that you have the information you need to answer the question
C95 = (1 + 9.2/100) *1000
C94 = number of cameras produced in 94
A manufacture produced x percent more video cameras in 1994 than in 1993 so C94 = (1+x/100)C93
y percent more video cameras in 1995 than in 1994
so C95 = (1+y/100)C94 ---> C95 = (1+y/100)(1+x/100)C93
you are given the value of C93, so in order to calculate the value of C95 you need to know (1+y/100)(1+x/100)
use FOIL in that expression
(1+y/100)(1+x/100) = 1 + (yx/10000) + y/100 + x/100 (1)
with this information take a look at the statements
statement I
xy=20
can you know the value of the expression just with that information? no
insufficient
statement II
compare the two expressions
x+y+xy/100 = 9.2
1 + (yx/10000) + y/100 + x/100
can you transform the first expression to get the second one?
divide everything by 100
x/100 + y/100 + xy/10000 = 9.2/100
sum 1 to both sides
if you compare now the both expressions
1 + (yx/10000) + y/100 + x/100
1 + x/100 + y/100 + xy/10000 = 1 + 9.2/100
you see that you have the information you need to answer the question
C95 = (1 + 9.2/100) *1000