Re: If a is positive integer, can a be expressed as the product of two int
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15 Jan 2020, 00:39
Given :
a=mn, where m & n are greater than 1 (m&n>1)
from st1 -> a is even i.e a = 2,4,6,8,10.....
lets take it one by one :
a = 2 ----> mn = 2 ----> 2*1 = 2 (not valid --> condition is m & n >1)
a = 4 ----> mn = 4 ----> 2*4 = 2 (valid)
from these solutions, we can see there is no consistency, so NOT SUFFICIENT
from st2 -> 7 < a < 11, which means values of a are {8,9,10}
lets take it one by one :
8 = possible factors = 1,2,4,8 = (1*8);(2*4);(4*2);(8*1) = 1 being factor of 8, makes it against the cond
& so not valid
9 = possible factors = 1,3,9 = (1*9);(3*3);(9*1) = 1 being factor of 9, makes it against the cond & so
not valid
10 = possible factors = 1,2,5,10 = (1*10);(2*5);(5*2);(10*1) = 1 being factor of 10, makes it against the cond & so not valid
so a ={8,9,10} results a STRICTLY NO
Note : In DS, either STRICTLY YES or STRICTLY NO results a SUFFIECIENT RESULT
Therefore B is Suffient.
Please correct me if my approach or my answer is wrong.
Thank and kudos in advance