The sum of the length and girth of a rectangle box must be smaller than 96 inches. If the girth is one half the length, what is the length?

Familiarize:

sum of length and girth < than 96 inches

girth = 1/2 length

length?

Translate:

let x - length

  y - girth

Carry out:

x+y < 96

y = x/2

x + x/2 < 96

1.5x < 96

x<96/1.5

x< 64 

y = 64/2 = 32

Check:

x + y < 96

63 + 32 < 96  True

y= x/2

32=64/2

32=32 True

State:

The length should be less than 32 inches.