What Is the Expected Total Number of Errors in a Computer Code?

[lina29]

Homework Statement

A computer code consists of two blocks written independently by two programmers. Each block contains no errors with probability 0.6, one error with probability 0.3, and two errors with probability 0.1.
a. What is the probability that there are more errors in the first block than in the second block?
b. What is the probability that two blocks have an equal number of errors?
c. Compute the expected number of errors in the 1st block.
d. Let Z be the total number of errors in the code. Use your answer in (c) to find E(Z).

Homework Equations

For A-.27
B- .46
C- .5

All of which were correct

The Attempt at a Solution

I just don't understand what part d is asking am I supposed to compute the expected number of errors in the 2nd block (.5) and then add it with the first block getting .10

or is there another approach?

 

[Dick]

Well, .5+.5 isn't equal to 0.10.

 

[lina29]

sorry I knew that :) I meant 1. would that be correct?

 

[Dick]

sorry I knew that :) I meant 1. would that be correct?

I think so. Expected total number of errors is the sum of the expected number of errors in the two blocks.