The simple interest formula is:
A = P(1 + rt)
where A is the final amount, P is the principal, r is the annual interest rate (as a decimal) and t is time in years.
Substituting with P = 1,300, r = 0.06 and t = 3, we get:
A = 1,300(1 + 0.06*3)
A = 1,300*1.18
A = 1,534
The final amount will be $1,534