Using google translate:
When photocopying a credential, it is first enlarged to triple and subsequently the resulting copy is halved. What is the final effect on the original credential? If the credentials is a rectangle of 10 by 6 cm. What area will you have in the first photocopy? And in the second?
Original: 10 by 6 cm ; Area = length * width = 10 x 6 = 60 cm²
first copy: enlarged to triple
10 x 3 = 30
6 x 3 = 18
30 x 18 = 540 cm²
second copy: halved
30 x 1/2 = 15
18 x 1/2 = 9
15 x 9 = 135 cm²
Answer:

Step-by-step explanation:
the mean is given by:

In our case this is:

side note: the main difference between sample mean and population mean is in the 'context'. However, the method to calculate them is the same.
By context I mean: if this the items are taken from some larger category for example: the ages of a few 'students' from a 'class'. Here 'students' are the sample from a larger set that is 'class'. The mean of the 'few students' will be called sample mean. In contrast, if we take the mean of the ages of the whole class then this is called population mean. (population mean == mean of the whole set)
In our case we aren't told exactly where these numbers come from, is this the whole set or a sample from it, the lack of context allows us to assume that the mean can either be population mean or sample mean. So we can safely use any symbol
or
.
120 sunny days if there were 60% of em in 200 days