Let the speed of the joker initially be x mi/hr
after reduction, the new speed will be: (x-1) mi/hr
but
time=(distance)/(speed)
hence :
Total time taken will be:
4/x+5/(x+1)=41/20
solving for x we get:
x=21.585 mi/hr
thus the initial speed was 21.585 mi/hr after reduction the new speed was 20.585 mi/hr
Short Answer: y = 36°
Remark
What an interesting question!! The first thing you have to do is find out what the interior angle of a regular pentagon is. After you have done that, you can calculate y.
Method.
The exterior angles of a regular figure add up to 360°.
Step One
Find out the size of the exterior angles of a regular pentagon.
There are 5 such angles. They add up to 360°
5x = 360 Divide by 5
x = 360 / 5
x = 72°
Step Two
Find out the value of the interior angles of a pentagon.
Method
The interior and exterior angles add up to 180°
Exterior Angle + Interior Angle = 180°
Exterior angle = 72 degrees
72° + Interior Angle = 180° Subtract 72 from both sides.
Interior Angle = 180° - 72°
Interior Angle = 108°
Step Three
Solve for y.
There are 3 tiles each with an angle of 108° that are placed together. So y + 3 interior angles = 360°
y + 3*interior angles = 360°
y + 3*108 = 360
y + 324 = 360 Subtract 324 from both sides.
y = 360 - 324
y = 36°
(x - 8)^2 = 144
take the sq rt of both sides
x - 8 = 12
x = 12 + 8
x = 20
20 feet by 20 feet
Three times the difference of a number and four.
or
Three times the quantity of four less than a number n.
