Final answer:
The correct answer to express the ratio of 100 pens to 120 pencils in lowest terms is option A, which is 5:6 after both terms are divided by their highest common factor, 20.
Step-by-step explanation:
The correct answer is option A. To find the lowest terms for the ratio of 100 pens to 120 pencils, we look for the highest common factor that both numbers share.
To express the ratio of 100 pens to 120 pencils in lowest terms, you need to find the greatest common factor (GCF) of the two numbers. In this case, both 100 and 120 are divisible by 20. Dividing both numbers by 20 gives you 5 and 6, respectively. Therefore, the lowest terms ratio is 5:6.
In this case, both numbers are divisible by 20. So, if we divide both terms of the ratio by 20, we get 100 ÷ 20 = 5 and 120 ÷ 20 = 6. Thus, the ratio of 100 pens to 120 pencils in lowest terms is 5:6.