Q. The number of binary operations on a set with 5 elements is greater than 1018.(A) true(B) false
Define Binary Operation: A binary operation on a set with 5 elements can be thought of as a function from the Cartesian product of the set with itself (5×5=25 possible input pairs) to the set (5 possible outputs for each input pair). To find the total number of binary operations, we need to calculate the number of functions from a set of 25 elements to a set of 5 elements.
Calculate Total Functions: Each of the 25 input pairs can be mapped to any of the 5 elements in the set. Since each mapping is independent, the total number of binary operations is 5 raised to the power of 25.
Exponential Calculation: Calculate 525 using the property of exponents. This is a large number, so we can use logarithms or a calculator to approximate if necessary. However, for the purpose of comparison to 1018, we can reason about the magnitude of the number.
Comparison with 1018: We know that 525 is much larger than 518 because raising a number greater than 1 to a higher power will always result in a larger number. Since 5 is greater than 1, 525 is greater than 518.
Evaluate 525 vs 1018: Now, we compare 518 to 1018. Since 518 is clearly less than 1018 (because 5 < 10), we need to determine if the additional power of 7 (from 518 to 525) is enough to make 525 greater than 1018.
Utilize Exponent Properties: To compare 525 to 1018, we can use the fact that 1018=(5×2)18=518×218. We want to know if multiplying 518 by 218 makes it smaller or larger than 525.
Final Comparison: Since 218 is a large number, and we are comparing it to 57 (the difference between 525 and 518), we can see that 218 is much smaller than 57. This is because 23 is 8, and 53 is 125, and 125 is significantly larger than 8. Therefore, 57, which is 573 raised to a power more than twice that of 574, is much larger than 218.
Conclusion: Therefore, 525 is indeed greater than 1018, and the statement "The number of binary operations on a set with 5 elements is greater than 1018" is true.