Question

2. Test the divisibility of the following numbers.
a) 1587 by i) 3 ii) 9
b) 5500 by i) 4 ii) 8
c) 10824 by 11
d) 3060 by i) 2 ii) 5 iii)10
e) 4335 by i) 2 ii) 3 iii) 6​

Answer 1

Step-by-step explanation:

a)1587

1+5+8+7=21

sum of the digits is divisible by 3

hence the number 1587 is divisible by 3

and sum is not divisible by 9

so the number 1587 is not divisible by 9

b) 5500

last 2 digits divisible by 4

so the number 5500 is divisible by 4

last 3 digits i.e. 500 not divisible by 8

hence the number 5500 is not divisible by 8

c)10824

sum of the digits at odd places= 1+8+4

= 13

sum of the digits at even places= 0+2=2

so the difference= 13-2 = 11

hence the number 10824 is divisible by 11

d)3060

last digit is 0 hence divisible by 2, 5 and 10

e) 4335

last digit is 5 hence number is not divisible by 2

4+3+3+5= 15

sum of the digits is divisible by 3 so the number 4335 is divisible by 3

as the number is not divisible by both 2 & 3 it is not divisible by 6.

Answer 2

Answer:

if the sum of the digits is equals to a multiple of 3 or 9 then it is a multiple of 3 or 9 then it is a factor of 3 or 9 free last two digits 0 otherwise a multiple of 4 then it is a multiple of 4 if the last three digits are zero or a multiple of 8 then it is a multiple of 8 if the last digit is even then it is a multiple of 2 if the last digit is 5otherwise 0 then it is a multiple of 5 if the last digit is zero then it is a multiple of 10 if a digit is multiple of both 2 and 3 then it is a multiple of 6 if the odd place values and even place values are added and subtracted answer is 0 or a multiple of 11 it is a multiple of 11