Answer:
51 rows
Step-by-step explanation:
Given
Length of bookmark = 20cm
Distance between beads = 4mm
Required
Number of rows of beads
First, the distance between the rows of beads must be converted to cm
if 1mm = 0.1cm
then
4mm = 4*0.1cm
4mm = 0.4 cm
This means that each row of beads is placed at 0.4 cm mark.
The distance between each row follows an arithmetic progression and it can be solved as follows;

Where
(The last term)
(The first term)
(The distance between each row of beads)
n = ?? (number of rows)
Solving for n; we have the following;
becomes


DIvide both sides by 0.4



Add 1 to both sides


Hence, the number of rows of beads is 51
the whole statement is true, make sure you read all of your choices next time and list them below.
Step-by-step explanation:
Below is an attachment containing the solution
The temperature went up 29°C, which represents a positive 29. Then the temperature fell 29°C, which represents a negative 29. The average temperature rose and fell the same amount. The absolute values are the same, so the difference is 0.