We have a proportion: 60/?= 20/100
Cross multiply:
20*?= 60*100
⇒ ?= 60*100/20= 300
60 minutes is 20% of 300 minutes~
Answer:

Step-by-step explanation:
We are given that
Radius of end of a log, r= 9 in
Error,
in
We have to find the error in computing the area of the end of the log by using differential.
Area of end of the log, A=


Now,
Approximate error in area

Using the values


Hence, the possible propagated error in computing the area of the end of the log
The answer to this question is 12y.