How do you do that? it does not explain

It is basically telling you to write the fraction as a decimal or the decimal as a fraction.

Step-by-step explanation:

As for number 1, it says that 1/10 is 0.1 as a fraction.

For number 2 you would turn 1/5 as a decimal. (Answer - 0.2)

For number 3, you would turn the decimal 0.25 into a fraction. (Answer - 1/4)

For number 4, you would turn 1/2 into a decimal. (Answer - 0.5)

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.