Answer:
Step-by-step explanation:
Given the function f(m)=20-0.25m to represent the amount of money f(m) she has left after talking m minutes, the zero of the equation can be gotten by setting f(m) to 0
f(m)=20-0.25m
0 =20-0.25m
-20 = -0.25m
m = -20/-0.25
m = 80
Hence Trudy will have talked for 80minutes if she has no money left
There are nine possible combinations as follows: bb, bc, bt, cb, cc, ct, tb, tc, tt, each having a probability of 1/9. The four combinations with a cab exactly one time are: bc, cb, ct, tc. Therefore the probability that she'll use a cab exactly one time is: 4/9.
<span>-15 + n = -27
Add 15 to both sides so that the only thing remaining on one side is the variable n.
Final Answer: n= -12</span>
Complete Question
Let P (n) be the statement that a postage of n cents can be formed using just 4-cent stamps and 7-cent stamps. The parts of this exercise outline a strong induction proof that P (n) is true for n ≥ 18.
Show statements P (18), P (19), P (20), and P (21) are true, completing the basis step of the proof.
Answer:
P(18) is true
P(19) is true
P(20) is true
P(21) is true
Step-by-step explanation:
a. When n = 18
18 cents can be formed using two 7cents and one 4cents
i.e. 2 * 7 + 4 = 18
So, P(18) is true
b. When n = 19
19 cents can be formed using one 7cents and three 4cents
i.e. 1 * 7 + 3 * 4 = 19
So, P(19) is true
c. When n = 20
18 cents can be formed using five 4cents
i.e. 5 * 4 = 20
So, P(20) is true
d. When n = 21
18 cents can be formed using three 7cents
i.e. 3 * 7 = 21
So, P(21) is true
