(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:
-3*3=-9
Step-by-step explanation:
Change 1.2%into decimal you will get 0.012
then multiply 350 by 0.012 you got the answer
then add the 0.012 with the 10 you will get 10.012
at the end round your answer to the whole number
Answer:
40
Step-by-step explanation:
8 muffins=1 cup of flour.
8 muffins × 5 cups = 40
Answer:
6
Step-by-step explanation:
6 is a multiple of three with only itself
