Math 365 Final

Question 1

(a+b)+c = a+(b+c)

Answer 1

Associativity property

Question 2

a+0 = 0+a = a

Answer 2

Additive identity

Question 3

a x (b+c) = ab + ac

Answer 3

Distributivity of multiplication over addition

Question 4

n/2 (n+1)

Answer 4

Guass’ problem

Question 5

S= a1/(1-r)

Answer 5

Sum for infinite geometric sequence

Question 6

a1r^(n-1)

Answer 6

nth term in geometric sequence

Question 7

Sn = (a1-a1r^n)/(1-r)

Answer 7

Sum of finite geometric sequence

Question 8

an = a1+d(n-1)

Answer 8

nth term for arithmetic sequence

Question 9

Whole # divisible by _____ if and only if the right most digit is 0

Answer 9

10

Question 10

Whole # is divisible by ___ if and only if the right most digit is 5 or 0

Answer 10

5

Question 11

Whole # divisible by ___ if and only if the right most digit is even

Answer 11

2

Question 12

Whole # is divisible by ___ if and only if the last 2 digits form a number divisible by 4

Answer 12

4

Question 13

Divisible by 8 if and only if ……

Answer 13

The last 3 digits form a number divisible by 8

Question 14

Divisible by 3 if and only if …..

Answer 14

The sum of the digits is divisible by 3

Question 15

Divisible by 9 if and only if …..

Answer 15

The sum of the digits is divisible by 9

Question 16

Divisible by 11 if and only if …..

Answer 16

(Sum of odd position #) - (Sum of even position #) = multiple of 11

Question 17

a+b=b+a

Answer 17

Commutative property