Question

(I) 21x7 is divisible by 9 then which digit can replace the x in four digit number 21x7​

Answer 1

Step-by-step explanation:

divisibility test for 9 sum of all digits must be 9

2+1+7=10=1+0=1

so we need to add 8 in it to make it 9

hence required number is 8

2187

2+1+8+7=18=1+8=9