Question

4. Using divisibility test find which of the following
numbers are divisible by 3 : by 9?
(a) 61809
(b) 21351
(c) 47592
(d) 2151
(e) 31795072​

Answer 1

Answer:

A) by 3

B) by 3

C) by 3 and 9 both

D) by 3 and 9 both

E) by none

Answer 2

Answer:

C 47592,

D 2151 both

Step-by-step explanation:

both are divisible by 3&9

add digital sum ( add digit like in C 4+7+5+9+2=27

means 3*3*3 means 9*3 that's divisible by both 3 &9)

take digital sum

A 6+1+8+0+9= 24 it's only divisible by 3 not 9

B 2+1+3+5+1= 12 it's also divisible by 3 not by 9

C 4+7+5+9+2= 27 it's divisible by both 3 &9

27 =9*3

D 2+1+5+1= 9 it's also divisible by both 3&9

E 3+1+7+9+5+0+7+2=34 it's not divisible by 3&9