TG EAMCET 2 May 2025 Shift 2 Paper

Step 1: Finding the average number of errors
The typist makes 1 mistake for every 10 pages. For 40 pages, expected errors =‌

40

10

=4.
Step 2: Setting up the Poisson distribution
We use the Poisson formula to find the chance of getting up to 2 errors when the average ( λ ) is 4 .
P(X=k)=‌

e−44k

k!

Step 3: Find probability of at most 2 errors
We need to calculate P(X≤2)=P(X=0)+P(X=1)+P(X=2) :
‌P(X=0)=‌

e−4⋅40

0!

=e−4
‌P(X=1)=‌

e−4⋅41

1!

=4e−4
‌P(X=2)=‌

e−4⋅42

2!

=8e−4
Add them up:
p=e−4+4e−4+8e−4=13e−4
Step 4: Multiply by e2 as asked in the question
e2p=13e−4×e2=13e−2