GMAT Practice Question: What is the remainder when 3^24 is divided by 5 ?
Question
What is the remainder when 3^24 is divided by 5 ?
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Topics: remainders, exponents, number theory
Solution
Step 1
We translate the phrase "remainder when 3^24 is divided by 5" into an equation relating the divisor, quotient, and remainder.
5k + r = 3^24
Step 2
We calculate the remainder when 3^4 is divided by 5, since we will use that to simplify 3^24.
3^4 = 81 = 516 + 1 remainder of 3^4 divided by 5 = 1
Step 3
We express 3^24 as (3^4)^6 and use the remainder of 3^4 to find the remainder of the entire expression.
3^24 = (3^4)^6 = (516 + 1)^6 remainder = 1^6 = 1
Answer
1
