The image above represents P(A or B).

To compute for P(A or B), four essential parameters are needed and these parameters are **x _{A}, N_{A}, x_{B}** and

**N**.

_{B}The formula for calculating P(A or B):

**P(A or B) = P(A) + P(B)**

Where;

**P(A)** = ^{xA} ⁄ _{NA}

**P(B)** = ^{xB} ⁄ _{NB}

Let’s solve an example;

Find the P(A or B) when x_{A} is 9, N_{A} is 11, x_{B} is 6 and N_{B} is 12.

This implies that;

x_{A} = 9

N_{A} = 11

x_{B} = 6

N_{B} = 12

**P(A or B) = P(A) + P(B)**

P(A or B) = ^{xA} ⁄ _{NA} + ^{xB} ⁄ _{NB}

P(A or B) = ^{9} ⁄ _{11} + ^{6} ⁄ _{12}

P(A or B) = ^{9(12) + 6(11)} ⁄ _{(11)(12)}

P(A or B) = ^{108 + 66} ⁄ _{132}

P(A or B) = ^{174} ⁄ _{132}

Dividing the numerator and denominator by **6**

P(A or B) = ^{29} ⁄ _{22}

P(A or B) = 1.318

Therefore, the **P(A or B) **is **1.318.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the P(A or B).

To get the answer and workings of the P(A or B) using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 1,500 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Probability**** **under **Mathematics****.**

Now, Click on **P(A or B) **under **Probability**

The screenshot below displays the page or activity to enter your values, to get the answer for the P(A or B) according to the respective parameters which are the **x _{A}, N_{A}, x_{B}** and

**N**.

_{B}Now, enter the values appropriately and accordingly for the parameters as required by the **x _{A}** is

**9, N**is

_{A}**11, x**is

_{B}**6**and

**N**is

_{B}**12.**

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the P(A or B) and presents the formula, workings and steps too.