Final answer:
Multiplying a number by 0.65 is equivalent to a 35% decrease from the original number. Therefore, the answer is (a) 35%.
Step-by-step explanation:
The question asks what percentage decrease is equivalent to multiplying a number by 0.65. To find this, we compare the result of multiplying by 0.65 to the original number, assuming the original number is 1 (or 100%).
When we multiply 1 by 0.65, we get 0.65, which means the new value is 65% of the original. To find the percentage decrease, we subtract the new percentage (65%) from the original percentage (100%):
100% - 65% = 35%
So, multiplying by 0.65 is the same as decreasing by 35%, which makes the answer to the question (a) 35.