Quiz 3 question 3 quant

GRE Quant Problem Solving
1

Hi all, Please help me understand for this question why 7^77/5 used a pattern recognition of 2,4,3,1 and not 7,9,3,1 if our unit digit was 7?

Thanks!

2

Can you post a picture of the full question?

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What is the remainder of 7^77/5?

4

You’re right that the pattern for 7 is 7,9,3,1

However we need to remainder pattern:

7/5 → remainder 2
9/5 → remainder 4
3/5 → remainder 3
1/5 → remainder 1

Does this help?

5

So I just need to subtract the pattern number by the denominator and if a number doesn’t have a remainder the pattern number is the “remainder”?