His mistake is he didn't make 6/10 to 60/100 he added them without changing the 6/10
Answer:
B
Step-by-step explanation:
The best - well, only way- is to check a few points.
Namely -1 (unless your eyesight is really poor!), 0, 1, 2, and 3.

Now you can mark all these points in each graph (well, you could if they were on paper and not on a screen) and see which one of the lines passes through all of them. Spoiler alert, it's the B graph.
A represents
, B is the one you want, C is
and D looks like 
Answer:
The man traveled 20km by train.
Step-by-step explanation:
If x is the distance he traveled by train, you can write this equation to represent the situation:

Then, you can simply solve for x:

The man traveled 20km by train.

Answer:
Answer is D = 121.51
Use the Compound Interest Formula
A = P (1 + (R/12)/100)^(12*n)
Run 2 case
P = 1700
R = 18.7, R = 12.5
n = 1 (as the problem is asking over the course of a year)
Solve for A for both the R and subtract the two values of A to obtain ~121.51
Step-by-step explanation: