Question

1)if least prime factor of `a' is 3 and least prime factor of `b' is 7,then the least prime factor of (a+b) is _______________
a) 2 b) 3 c) 5 d) 11
i want ans in a clear manner then only i will pick as best

Answer 1

Lets first talk about a since on prime factorisation it yeilds 3 as least prime no.,all other prime factors must be odd only since 2 is not there the resulting no. will be an odd no.( product of odds=odd) Similarly in b 7 is the least prime no. So it must be an odd no. Sum of two odd no. is even i.e (a+b) is even . So its prime factor (least) is 2

Answer 2

Answer:

a) 2

Step-by-step explanation:

least prime factor of "a" is 3 and least prime factor of "b" is 7

so sum of least prime factors of a and b = 3+7 = 10

and least factor of 10 is 2

so least factor of a + b is also 2

HoPe ThIs HeLpZ...