Respuesta :

Answer: Susie walked 4000 kilometers on day 18 of her program

Step-by-step explanation:

The question explains an arithmetic progression of  Susie's walk program

Now the nth term of an AP is given as

an = a1 + (n - 1 ) d

a1  =First term = 600 m

common difference , d =200

The 18th day of her program will be

a18 =  600+ (18 - 1 ) 200

a18 = 600+ 17 x200

a18 = 600+3,400

a18 = 4000