Information from question
Initial population: 170
Increase: 3% (=x1.03)
Years: 5
Method
Formula: initial value x increaseyears
170 x 1.035 = 197 sheep
Proof
170 x 1.03 = 175.1 (1st year)
175.1 x 1.03 = 180.35 (2nd year)
180.35 x 1.03 = 185.76 (3rd year)
185.76 x 1.03 = 191.34 (4th year)
191.34 x 1.03 = 197.08 (5th year)
So answer is 197 sheep