(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 
.
The simple interest earned in year 1 is 7.5. The simple interest earned in year 1 is $7.50. The total interest earned at the end of year 4 is $30.00
<h3>How to calculate a simple interest amount?</h3>
If the initial amount (also called as principal amount) is P, and the interest rate is R% annually, it is left for T years for that simple interest.
3% simple annual interest paid on $250
A 2-column table with 4 rows.
Column 1 is labeled Year with entries 1, 2, 3, 4.
Column 2 is labeled Total Interest Paid with an entries question mark, 15 dollars, 22 dollars, and 50 cents,
The simple interest earned in year 1 is calculated as
The first one is (0.03)(250) = 7.5
The simple interest earned in year 1 is
The second one is $7.50
The total interest earned at the end of year 4 is
The third one is $30.00
Learn more about interest here:
brainly.com/question/11897800
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22.3694
Step-by-step explanation:
each mps is 2.23694 x 10 = 22.3694
Area of a circle = pi * radius^2
r = d/2 = 8/2 = 4 inches
Area = 3.14(4^2) = B. 50.2 inches
X equals 19 hope this helps
