(a) 
since 13 is prime.
(b) 
, and there are 81/3 = 27 multiples of 3 between 1 and 81, which leaves 81 - 27 = 54 numbers between 1 and 81 that are coprime to 81, so 
.
(c) 
; there are 50 multiples of 2, and 20 multiples of 5, between 1 and 100; 10 of these are counted twice (the multiples of 2*5=10), so a total of 50 + 20 - 10 = 60 distinct numbers not coprime to 100, leaving us with 
.
(d) 
; there are 51 multiples of 2, 34 multiples of 3, and 6 multiples of 17, between 1 and 102. Among these, we double-count 17 multiples of 2*3=6, 3 multiples of 2*17=34, and 2 multiples of 3*17=51; we also triple-count 1 number, 2*3*17=102. There are then 51 + 34 + 6 - (17 + 3 + 2) + 1 = 70 numbers between 1 and 102 that are not coprime to 102, and so 
.
Answer:
b
Step-by-step explanation:
The plant started to wither 35 days after it was planted.
Answer:
In 4 months the cost of both gyms will be the same.
Step-by-step explanation:
At first we need to model the function to calculate the cost of the 2 gyms.
Slope-intercept equation of linear function
where
slope of line
y-intercept
Let linear function to calculate total cost of gym be:
where
total cost of gym
cost per month (slope)
number of months
start-up fee (y-intercept)
For Gym 1
, 
For Gym 2
, 
In order to find the number of months the cost of both gyms will be the same, we need to equate both functions and solve for number of months 
So,
In 4 months the cost of both gyms will be the same.
True, because without the preparation for retirement, there will be nowhere to store retirement funds.
