To find the total number of computers shipped (c) when the number of delivery trucks (t) is 10, you can use the relationship given in the description.
The formula for total computers shipped can be expressed as:
\[ c = 42 \times t \]
Now, substituting \( t = 10 \):
\[ c = 42 \times 10 \]
Calculating this gives:
\[ c = 420 \]
So, the value of \( c \) when \( t = 10 \) is \( 420 \).