Data Sufficiency

Jack and Mark both received hourly wage increases of 6 percent. After the wage increases, Jack's hourly wage was how many dollars per hour more than Mark's?

(1) Before the wage increases, Jack's hourly wage was $5.00 per hour more than Mark's.

(2) Before the wage increases, the ratio of Jack's hourly wage to Mark's hourly wage was 4 to 3.

Please help...

Thanks.

Maybe not the best approach but hopefully got the right answer

Let hourly wage of Jack=x and Mark=y

Question asks how much more is 1.06(x) than 1.06(y)[After wage increase]


(1) states that x=y+5 Substitute this in 1.06(x) and u get

1.06(y+5)=1.06y+5.30 -> Sufficient because it clearly says that after the increase x is 5.30 more than y


(2) Not Sufficient because x and y can have different values and since the question does not ask the ratio but the exact amount, this statement is of no use.

Hope it helps!!

I got A as well. I didn't go through as much algebra though. I just wrote:

Before increase ---> J = 5 + M

5 x 6% + 5 = 5.30.

Second statement is insufficient for the same reason as above. Nothing more can be said.

I agree with A but what I see here is that the initial value was assumed to be 1x and 1y so 6 percent increment would obviously be 1.06x and 1.06y.

But if we assume the intial value to be 100x and 100y in that case we would have 106x and 106y. Then the answer would be different.

I ask this question specifically because I have seen one DS which threw one option out just for this reason.

dferm wrote:Jack and Mark both received hourly wage increases of 6 percent. After the wage increases, Jack's hourly wage was how many dollars per hour more than Mark's?

(1) Before the wage increases, Jack's hourly wage was $5.00 per hour more than Mark's.

(2) Before the wage increases, the ratio of Jack's hourly wage to Mark's hourly wage was 4 to 3.

Please help...

Thanks.

let jack's wage=x; mark's wage=y;

1) x=5+y, after hourly increase of 6%, mark's wage would be 1.06y,

and jack's wage would be(5.30+1.06y)

therefore, jack's hourly wage is 5.30$ more than mark;(jack's wage after increase-mark's wage after increase) (5.30+1.06y-1.06y)

hence 1 is sufficient to answer the question

2) here ratio of x/y=4/3; now here for different values of x different results are possible, for example consider x=8,y=6;

therefore jack's salary after hourly increase is (1.06)8=8.48, mark's salary after hourly increase(1.06)6=6.36;

therefore difference= 2.12;
now consider x=12, y=9;
therefore jack's salary after hourly increase is (1.06)12=12.72; marks salary after hourly increase is(1.06)9=9.54

difference= 12.72-9.54=3.18;

as here different results are possible for different values of x and y, hence 2 alone is not sufficient to answer the question.

hence answer should be A

I have a doubt. How do we know that there was just one hour increase. Might be that they received 3 hour increases. In that case, increment = (1.06)^3 (J-M)