JEE MATHEMATICS MCQ: PERMUTATIONS

1 Medium

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Application +4 | -1

The number of ordered pairs

(m, n)

m, n \in\{1,2, \ldots, 100\}

such that

7^m+7^n

is divisible by 5, is

View answer and explanation

Correct option: C

2500

Option C (2500) is correct because it represents the number of ordered pairs (m, n) such that 7^m + 7^n is divisible by 5, which is determined by analyzing the cyclical pattern of the last digit of 7^r.

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