Question

1. Which of the following statements are true?
(a) If a number is divisible by 3, it must be divisible by 9.

(b) If a number is divisible by 9, it must be divisible by 3

(c) A number is divisible by 18, if it is divisible by both 3 and 6.

(d) If a number is divisible by 9 and 10 both, then it must be divisible by 90.

(e) All numbers which are divisible by 4 must also be divisible by 8.

(f) If two numbers are co-primes
, at least one of them must be prime.

G) all numbers which are divisible by 8 must also divisible by 4

h) if a number is exactly divides two numbers separately it must exactly divide their sum

I) if a number exactly divides the sum of two numbers it must exactly divide the two numbers separately

SPAMS WILL REPORTED​

Answer 1

Answer:

1. true

2.T

3.I DON'T THINK SO ACTUALLY I DON'T KNOW

4.F

5.T

6.T

7. T

8.T

9.T

Answer 2

SOLUTION:

i) false because there are plenty of numbers that are divisible by 3 but not divisible by 9. eg.30.

ii) true

iii) false, number 30 for example, is divisible by 3 and 6 but not divisible by 18.

iv) true

v) false, we know that two numbers having only 1 as a common factor are called co.prime numbers, so not necessary that one of them must be prime.

vi) false, example number 36 is divisible by 4 but not divisible by 8.

vii) true

viii) true

ix) false, example number 5 exactly divides the sum of two number 2 and 3 but not exactly divide these two numbers