since this is a multiplication, all the numerators are just factors of the product numerator and all denominators are just factors of the product denominator, so we can simply reorder them some, without changing the product.

20 x 1/2 = 10
There are 10 rows that are planted with corn.
Answer:
HCF×LCM=a×b
6×60=a×b
a×b=360
So the numbers are whose product is 360 and LCM is 60
These two numbers can be 6,60 or 12,30