Always use this formula for work and rates.

W=rt

W= work, r= rate, t= time

this problem has k as units of work, and j and unit for rate, plug those in

K=jt
we are comparing this to
K+10= (J+10)t
we want to isolate time for each equation

for the first equation
K/j=t

for the second equation
(K+10)/(j+10) = t

now just plug in numbers
recall that K is greater than J,

Plug in K for 6 and 5 for j

then for the first equation
6/5=t

for the second equation

16/15=t

compare 6/5 and 16/15, you will see that 6/5 is greater,
the answer is A

So we are looking for \(\frac{k}{j}\) and \(\frac{k+10}{j+10}\) where k>j meaning \(\frac{k}{j}>1\)..
If we add the same positive number, which is 10 here, to both the numerator and denominator of a fraction >1, the new fraction with the higher numerator and denominator is lower..
For example... between 2/1 and (2+10)/(1+10)=12/11, 2/1 is bigger..

Check more on the same concepts from the following link
https://gre.myprepclub.com/forum/effects-o ... 8a17db9825

Answer: A
0 < j < k
A: The time it takes to read k words at j words per minute
B: The time it takes to read (k + 10) words at (j + 10) words per minute
The only thing that we need is comparing fractions, disregarding the time (as time in both A and B is minute)
A: k /j
B: k+10 / j+10
If we have 1000/3 than we add 1000000 to both nominator and denominator, we will have:
1001000 / 1000003 which is going to 1, the more the added value is, the nearer the fraction is to 1.
By these we can say that k+10 / j+10 is nearer to 1 than k/j and as k is bigger than j, the fraction k/j is something more than 1, Thus, A is bigger than B.

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