中等MATH-NUMB-011
A town has population 2.4 × 10^5. After a 5% increase, which figure is correct?
A. 2.45 × 10^5
B. 2.52 × 10^6
C. 1.2 × 10^6
D. 2.52 × 10^5✓ 答案
解說
Multiply by 1.05: 2.4 × 1.05 = 2.52, and the power of 10 is unchanged, so the population is 2.52 × 10^5. Adding 0.05 to 2.4 is not a 5% increase.