Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

There is an easier approach/formula for such problems rather than working out all the possible combinations.

If the probability of success in each trial is p, then the probability of r successes in n trials is ^nC_rp^rq^{n-r}

Since, the question asks us to find out probability for at least 4 heads, it gives rise to two scenarios. r = 4 heads exactly or r = 5 heads exactly. And ADD the scenarios finally.

We can infer from the question that probability of heads = p = 0.6, r = 4 or 5, n=5 . Obviously probability for tails = q = 0.4.

I’m considering a very difficult decision. Insanity maybe? I don’t know. I’m thinking about retaking the GMAT before Round 2 deadlines with a goal of scoring...

Quick update from me... I had my first INSEAD alumni interview earlier this week with the second (and final!) one scheduled for tomorrow. I’ve been doing...

I attended a portfolio workshop hosted by Business Design club today. Competing against thousands of MBA students with the entire world, you need more than your resume and coverletter...

so actually alongside the MBA studies, I am studying for personal trainer exam in December as a side. I can basically only read when I’m in the subway...