Hi
Here are my two cents for this question
We are asked if product of rs if mulitple of 25k
so if rs =25k,
this can be possible in following scenarios
(a) if r is multiple of 25 or
(b)s is multiple of 25 or
(c)r and s are each multiple of 25
(d)or r and s are each multiples of 5.
Now statement 1 gives us that difference of two integers is multiple of 5
Essentially they could be each not multiple of 5 or 25 and we could have difference which is multiple of 5 or we could have each multiple of 5 or 25 and we could have difference which is multiple of 5
here is what i mean .
if r= 21, s=11 r-s = 10 which is multiple of 5 or we can have r= 30 s =5 difference is 25 which is multiple of 5
From statement 2 we have either r or s is a multiple of 5
Now combining both we have
r or S is multiple of 5,
then
if r is multiple of 5 then s needs to be multiple of 5. because multiples of 5 can have either 0 or 5 in its units place . so if r takes 0 or 5 in its units place s also needs to take 0 or 5 in its unit place. Which makes r and s both multiples of 5
Hence both statements are required to answer the question .
Probus
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Probus
~You Just Can't beat the person who never gives up~ Babe Ruth