Question

Which of these expressions is a not way to calculate 25% of 9100?

A)9100 x 0.25
B) 9100/4
C)9100 x 2/5
D)9100 x 25/100

Answer 1

Expression C (9100 x 2/5) is not a correct way to calculate 25% of 9100 because 2/5 represents 40%, not 25%, which is the required percent to calculate.

Step-by-step explanation:

The question asks which of the provided expressions is not a way to calculate 25% of 9100. To find 25% of a number, you can multiply the number by 0.25, divide the number by 4, or multiply the number by the fraction 25/100 since all these operations will yield the same result (which is the definition of 25 percent).

• Expression A (9100 x 0.25) is correct because 0.25 represents 25% as a decimal.
• Expression B (9100/4) is correct because dividing by 4 is the same as calculating 25% (one quarter).
• Expression C (9100 x 2/5) is not correct because 2/5 represents 40%, which is different from 25%.
• Expression D (9100 x 25/100) is correct because 25/100 simplifies to 25%, which is exactly what we want to calculate.

Therefore, Expression C is the one that does not correctly calculate 25 percent of 9100.