we are given

Firstly , we will multiply both sides by 5

now, we can simplify it


now, we can solve for n
.............Answer
This is an A. <span>observational study. They are observing the use of cell phones differs between people with or without cancer.
Happy studying ^-^</span>
Step-by-step explanation:
here,
31 cup of milk require 41 cup of water.
1 cup of milk require 41/31 cup of water.
so, 41/31 cup of water is required for 1 cup of milk.
<em>hope</em><em> </em><em>u</em><em> </em><em>get</em><em> </em><em>it</em><em>.</em><em>.</em>