A ball will be drawn from the bag containing 20 balls numbered one through 20 if each ball is equally likely to be drawn what is the probability that the number on the bar will be drawn even or less than five

3/5

Step-by-step explanation:

There are 20 balls, numbered 1 through 20.

Of these, 10 are even, 4 are less than five, and 2 are both even and less than 5.

So the probability is:

P(even or <5) = P(even) + P(<5) − P(even and <5)

P(even or <5) = 10/20 + 4/20 − 2/20

P(even or <5) = 12/20

P(even or <5) = 3/5

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places