One number is one-third another. Write an expression that represents the greater number.

3y

Step-by-step explanation:

To write an expression, define variable. x will be "another number". This means "one number that is 1/3" is 1/3 * x.

1/3 x represents the smaller number.

To represent the larger number, use the inverse or reciprocal. y will be the smaller number. The larger number will be 3*y or 3y.