Help me on number 3 I don't get it and I really need to know and please explain too

Apark is in the shape of a rectangle. the park authorities are planning to build a 2-meter-wide jogging path in the park (shown as the shaded region in the image). what is the area of the jogging path? plz

Jacks bank statement shows an account balance of -$25.50. which describes the magnitude, of size, of the debt in dollars

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours