Simple current and charge circuit question

[JFonseka]

Homework Statement

If the current in a wire is given by the following functions of time, what charge passes
a given point from t=0 to t=10 seconds? (i is in Amps and t in seconds). Show units
for charge.

i(t) = 4t + 5

Homework Equations

Nothing really

The Attempt at a Solution

0 seconds: 5A
10 seconds: 4x10 + 5 = 45A

Therefore 50C have passed through the wire in total.
But the answer at the back for my question says 250C, I don't get it.

 

[lavalamp]

You have to integrate that formula with respect to time, then plug in a value for t.

 

[JFonseka]

Ah...now I see that I get the right answer...but why do we have to integrate. I don't get it.

 

[JFonseka]

Nvm I just realized. This is what happens when you stay out of touch with physics for 4 months.