This is the concept of financial mathematics, the simple interest rate is given by:
S.I.=(PRT)/100
where:
P=principle=$2500
R=rate=5.5%
T=time=1 year
Hence;
S.I.=(5.5*2500.1)/100
=$137.5
Thus the total amount he had after 1 year will be:
2500+137.5
=$2,637.5
Step-by-step explanation:

• y2 → -1
• y1 → 5
• x1 → 4
• x2 → -3

Answer:
Option D
Step-by-step explanation:
If the whole grid is considered to be 1,
Each small grid will value = 
There are 72 shaded grids which represent the hundreds = 0.72
When these grids have been divided into 9 equal rows, number of grids in each row = 8
And the value of 8 grids in each row = 0.01 × 8 = 0.08
So the equation is,
0.72 ÷ 9 = 0.08
Therefore, equation represented by the model will be Option (D).