I = p r t
Investment = principal × rate × time (in years)
So in this case, we do not know what the total investment is so we know everything to the right of the equal sign)
I = 7500 (how much he invests in) × 0.0275 (2.75%) × 1 (annual interest)
7500 × 0.0275 = 206.25 × 1 = 206.25
So 206.25 is I
(206.25 = 7500 × 0.0275 × 1)
Hope this helps!