To solve this problem, we need to first find the dimensions of the side of the blue and purple squares.
We're given that the purple (smaller) square has a side length of x inches.
We are also given that the blue band has a width of 5 inches.
Since the blue band surrounds the purple square on both sides, the length of the blue square is x+2(5)=x+10 inches.
The net area of the band is therefore the difference of the area of the blue square and the purple square, namely take out the area of the purple square from the blue.
Therefore
Area of band

[recall



or 20(x+5) if you wish.
Let x be the expected number
Number arriving = 3•5 x
Unexpected number 2•5 x
2•5 x = 105
10x = 420
x = 42______Option D
Lets calculate gear ration T2/T1
so the gear ratio will be 1.6 it simply means dat if u rotate large gears one full revolution it tends to turn another short wheel to 1.6 revs, so in ur qtion the large whell revs 100 den u must multiply wid 1.6*100= 160 revs