Answer:
$8000
Step-by-step explanation:
The method for calculating simple interest (I) is
I = 
where P is the principal, R is interest rate, T is time in years
here I = 1120, R = 3.5, T = 4 and P is to be found, thus
1120 =
( multiply both sides by 100 )
3.5 × 4 × P = 112000
14P = 112000 ( divide both sides by 14 )
P =
= $8000