CMA Foundation · Fundamentals of Business Mathematics and Statistics · Indices and Logarithms
If 5^(x) = 25^(y) and y = 3, then the value of 5^(x-4) is:
The value is 25. Since 25^3 equals 5^6, x is 6, so 5^(x-4) becomes 5^2, which is 25.
- A25Correct
- B5
- C125
- D625
Explanation
25^3 = 5^6, so x = 6. Then 5^(x-4) = 5^2 = 25. Option 625 uses x = 6 as 5^4 mistakenly; 125 uses x-3.
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