Probability is one of the easiest topics to score high in, yet many JAMB candidates skip it or get confused when they see the word “chance” or “likelihood.” But the truth is, JAMB rarely asks deep or complex probability questions. They mostly want to see if you understand basic ideas like how likely something is to happen.

This guide will help you understand what JAMB expects from you in probability questions, how to answer them correctly, and how to avoid common mistakes.

READ: JAMB Syllabus for Mathematics 2025/2026 PDF Download

What Probability Really Means

Probability simply measures how likely an event is to happen. If you toss a coin, there’s a chance it could land on heads or tails. That chance is what we call probability.

In simple terms:

Probability = (Number of favorable outcomes) ÷ (Total number of possible outcomes)

It’s always written as a fraction, decimal, or percentage between 0 and 1.

• 0 means “impossible.”
• 1 means “certain.”
• 0.5 means “50/50 chance.”

JAMB loves this formula and brings it often in simple formats.

How to Approach Probability Questions in JAMB

Let’s say you’re given a bag with 3 red balls and 2 green balls. What’s the probability of picking a red ball?

• First, find the total: 3 red + 2 green = 5 balls in total
• Then, find how many are red: 3
• So, probability of red = 3/5

That’s your answer. No long steps.

Most JAMB questions on probability follow this same method—basic counting and choosing.

Don’t Let English Confuse You

Sometimes, the way the question is written can make it look difficult. JAMB may say:

“A box contains 4 white, 5 black, and 1 blue marble. If one marble is picked at random, what is the probability that it is not black?”

Here’s what you do:

• Total marbles = 4 + 5 + 1 = 10
• Not black = white + blue = 4 + 1 = 5
• So, probability = 5/10 = 1/2

Even if it sounds tricky at first, break it down one step at a time.

Key Things You Must Remember

In JAMB, you’ll mostly see these types of probability problems:

• Tossing a coin
• Rolling a die
• Picking from a bag or box
• Choosing people or objects from a group

No matter the setup, the steps are the same:

1. Find the total number of possible outcomes
2. Count how many match what the question is asking
3. Divide favorable by total
4. Simplify your answer if needed

READ ALSO: How to Prepare for JAMB 2025 Mathematics and Pass with Ease

Final Words

Probability is not a hard topic, but it requires clear thinking. Don’t try to rush or guess. Just read the question slowly, understand what it’s asking, and use the simple probability formula.

If you practice a few past questions every day, you’ll start to recognize the patterns. And when it shows up in your JAMB 2025 exam, you’ll smile—because you’ll already know what to do.