Question

how the answer comes

Answer 1

$3^{25} + 3^{26} + 3^{27} + 3^{28}$

Take out common factor 3²⁵:

$3^{25} (1 + 3 + 3^2 + 3^3)$

Evaluate each term in the bracket:

$3^{25} (1 + 3 + 9 + 27)$

Add up the terms in the bracket:

$3^{25} (40)$

Since the number has 40 as a factor, it can be divided by 40

Answer: (D) 40

Answer 2

divide and multiply all by 3^25
we get,3^25(3^25/3^25+3^26/3^25+3^27/3^25+3^28/3^25)

=3^25(1+3¹+3²+3³)

=3^25(1+3+9+27)

=3^25(40)

now 40 is diviaible by 40
so it is divisible by 40