Before a salary hike, the weekly salary of a worker for 40

Question

Before a salary hike, the weekly salary of a worker for 40 hours in a week was as much as he is paid now for 35 hours of work in a week. What is the percent increase in his salary for an hour?

A. 11 1/3
B. 12 1/4
C. 13 1/5
D. 14 2/7
E. 15

KarishmaB · Accepted Answer

Say the worker used to get $40 for 40 hrs i.e. $1 per hr. 
Now he gets $40 for 35 hrs i.e. 40/35 = $8/7 per hr

Hike is $1/7 per hr i.e. (1/7)*100 = 14 2/7 %

PareshGmat · Answer

Earlier per hour salary = x, so total paid = 40x
New per hour salary = y, so total paid = 35y.
So, per information given, 
40x = 35y,

\frac{x}{y} = \frac{7}{8}

Salary increase = \frac{8-7}{7} = \frac{1}{7}

Salary increase percentage = \frac{1}{7}*100 = 14 \frac{2}{7} 
(Answer = D)

prasannajeet · Answer

280 is multiple of both 40 and 35 
so I would rather take this value as the salary.

40 hrs 280$ 
1 hr=7$

Similarly
35 hrs 280$
1 hr=8$

Now 8-7=1$ increase in salary per hour now to calculate %
1/7*100=14 2/7

Rgds
Prasannajeet

monirjewel · Answer

Suppose Per hour paid=x dollars,
So total paid 40x and 35x dollars
Now percent increase=(40x-35x)/35x=(5x/35x)*100=100/7=14.28...So D is the ans.

mvictor · Answer

i solved as above said:
1/7 is between 1/6 and 1/8
which means the increase is 12.5% < x < 16%
we can eliminate A and B right away.
since we have 7 as denominator, and since we need to find 100/7, we clearly see that 100 is not divisible by 7, and thus the answer choice should be a number with a denominator 7.

only D has such, and it falls between the given spread of increase.

MHI · Answer

Answer: D  
To make the question easier, we can select the easy numbers:
Weekly salary is 40 hrs x $35/hr = 35 hrs x $40/hr ⇒ an increase from $35 to $40 ⇒ %increase=(40-35)/35=5/35=1/7=0.142 or 14 2/7 %

Abhishek009 · Answer

Old Salary ( For 40 Hrs ) = New Salary ( For 35 Hrs ) = 280

So, Old Salary/ Hour = 7 and New Salary/Hour = 8

So, Percentage Increase is 1/7*100 =>  14 \frac{2}{7}

Hence, Correct answer must be (D)  14 \frac{2}{7}

kanusha · Answer

x$ = 560$ for 35hrs
1hr = 16$
640$ for 40hrs
 \frac{change}{original} = \frac{percent}{100} 
 \frac{80}{560} x 100 = \frac{100}{7} 
D

iliavko · Answer

I got 40=35X so x=8/7 how can I convert this fraction to "something/100" fraction? The denominator is not a factor of 100. 
Can I multiply 8/7*100 then divide by 7 to get 114.28?.. so the increase was 14.something percent.

I couldn't see that the increase was actually the 1/7th on top of the 7/7th.

Is the above method valid to transform fractions with an inconvenient denominator into A/100? (say the denominator was 4, I would simply multiply both den and num by 25 and get a clean /100 fraction) Do I make my doubt clear?..

Thank you!

KarishmaB · Answer

Note that 8/7 = 1 + 1/7 (can be done for all fractions greater than 1)
1/7 = 14.28% so 8/7 implies an extra 14.28%.

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Before a salary hike, the weekly salary of a worker for 40

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