Question

Prove that the sum 2+2^2+2^3+__________+2^2019+2^2020 is divisible by 30 .

Answer 1

Answer:

iv) The prime numbers between 60 and 100 are 61, 67, 71, 73, 79, 83, ... Rule: A number is divisible by 3 if the sum of its digits is divisible by 3. ... We have dividend = 1045 and divisor = 1520 ... Show that the following pairs are co-prime

Answer 2

Answer:

The given is sum is divisible by 30

Step-by-step explanation:

2+2^2+2^3+. . . . . . . . +2^2019 +2^2020

(2+2^2+2^3+2^4).(1+2^4+2^8+2^16+ . . . . . +2^404)

30.(1+2^4+2^8+2^16+  . . . . . +2^404)

The above is series is divisible by 30

Hence Proved.

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