There are five red balls, three yellow balls, and four green balls in a bin. In each event, you pick one ball from the bin and observe the color of the ball. The balls are only distinguishable by their colors. After observation, you put the ball back into the bin. What is the probability of choosing a red ball in an event? 

Step-by-step explanation:

step one:

Given the sample space, which is the value of individual number of colored balls in the bin

Red balls=5

Yellow balls=3 and

Green balls= 4

And the sample size is the sum of all the colored balls in the bin

The sample size S= {5+3+4}= 12

step two:

The probability of choosing a red ball in an event can be expressed as, the total number of the red balls over the total number of balls in the bin

P(r)= 5/12

Hence the probability of selecting a red ball in one event 5/12

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

7 ft 6 in means 7 1/2, because 6 in is 1/2 of a foot. 7 ft 8 in means 7 2/3 because 8 in is 2/3 of a foot. 23/3 = 7 2/3. 15/2 = 7 1/2.

23/3   *   15/2   = 57 1/2

step-by-step explanation: