Answer :
3/18÷7/21=3/18*21/7=3*21/18*7=63/126
No both numbers we can divide them by 7
63÷7/126÷7=9/18
Then also we can divide both numbers by 9
9÷9/18÷9=1/2
And the answer is 1/2
No both numbers we can divide them by 7
63÷7/126÷7=9/18
Then also we can divide both numbers by 9
9÷9/18÷9=1/2
And the answer is 1/2