n k product is 400
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IMO E.
nk = 400
a) n + k > 0 ( not true.. n and k can both -20 and their sum can be less than 0)
b) n<>K ( Not true... n and k can both be 20 or -20)
c) n or k is a multiple of 10 ( 400 can be written as 4*5*4*5 (=20*20) .. Which can be written as 16*25. So n or k may not be a multiple of 10)
d) If n is even , then k is odd (Not always.. if n is 20, k should be 20 which is even)
e) If n is odd , then k is even (Must be true. If n is 25(or 5), then k must be 16(80) which is even. ) Bcoz odd * even = even.
nk = 400
a) n + k > 0 ( not true.. n and k can both -20 and their sum can be less than 0)
b) n<>K ( Not true... n and k can both be 20 or -20)
c) n or k is a multiple of 10 ( 400 can be written as 4*5*4*5 (=20*20) .. Which can be written as 16*25. So n or k may not be a multiple of 10)
d) If n is even , then k is odd (Not always.. if n is 20, k should be 20 which is even)
e) If n is odd , then k is even (Must be true. If n is 25(or 5), then k must be 16(80) which is even. ) Bcoz odd * even = even.