Question

the product of two rational number is 1 if one of them is 4by5 then other is

Answer 1

Let second number be a

According to question

=> a* 4/5 = 1

=> a = 5/4

Second number = 5/4

Answer 2

let other rational no. be 'x'
according to question,
4/5*x=1
x=1*5/4
x=5/4