Answer:
52.38%
Step-by-step explanation:
Given that,
Total number of students in the class is 42
Out of 42, 10 like hamburgers, 22 like pizza, 8 like french fries, and 2 like salad.
We need to find the percentage of the class chose pizza. There are 22 student who like to have pizza. Required percentage is given by :

So, 52.38% of students chose pizza.
Answer:
0.50 kg of the material would be left after 10 days.
0.25 kg of the material would be left after 20 days.
Step-by-step explanation:
We have been given that the half-life of a material is 10 days. You have one 1 kg of the material today. We are asked to find the amount of material left after 10 days and 20 days, respectively.
We will use half life formula.
, where,
A = Amount left after t units of time,
a = Initial amount,
t = Time,
h = Half-life.




Therefore, amount of the material left after 10 days would be 0.5 kg.





Therefore, amount of the material left after 20 days would be 0.25 kg.
Find 20 percent of $20 by multiplying 0.20 x20
You get $4. That’s what he saved.