hey there!
Given ,
The length of rectangular desk = 6/7 meters
The width of rectangular desk = 8/9 meters
We know that ,
Area of rectangle = length x width
=> 6/7 x 8/9 = 16/21
So the answer is option (3)
Yes , we need to multiply 6/7 and 8/9 to get area of 16/21 which fits.