Insurance News
Brief insurance news and digest for the busy executives. A handy insurance news archive with main focus on Malaysia. Disclaimer: While all attempts are made to ensure the accuracy of the news herein, we will not be liable for any loss arising from the use of any information contained in this blog. You may reproduce materials published here provided the source (news.actuaries.com.my) is properly acknowledged.
Insurance Job Advertisements
Friday, 18 September 2009
Brain Teaser #1
For the brainy people out there, try this question, adopted straight from primary school mathematics competition:
"Find 8 prime numbers so that their sum is 100. What is the total of the smallest and the largest of these 8 numbers?"
The participants actually had 30 questions to answer in 20 minutes, so on average you have less than 1 minute to answer a question. But for this one, I give you as much time as you like. Post you answer in the Comment section below by showing the 8 numbers as well. See who gets the right answer first.
If you are convinced that there is no solution, please explain.
Labels: Brain Teaser
About Me
- Name: Teh Loo Hai
- Location: Kuala Lumpur, Malaysia
Loo Hai is an actuarial recruiter cum actuarial consultant. He has over 20 years of work experience gained in Malaysia and Australia in the actuarial, insurance, takaful and pension fields.
Previous Posts
- No news is good news
- Great Eastern hires takaful head
- UOB Life to be sold
- 30pc quota lifted for Allianz
- More actuaries are becoming CEOs
- Etiqa Takaful to expand in Asian region
- Star's article on RBC and liberalisation
- Retirement statistics
- Global Recovery Income Plan (GRIP)
- Charlie's interview with press
Subscribe to
Posts [Atom]
6 Comments:
5
5
7
11
13
17
19
23
ans:28
If repeats are allowed, is this the only possible solution?
If repeats are not allowed, what would be the solution?
3
7
7
11
13
17
19
23
1
3
5
7
11
13
17
43
The last 2 could vary (19,41) (23,37) (29,31).
So the total of smallest and largest can be 44, 42, 38 or 32?
Don't think 1 is a prime number though
There is no possible solution unless repeats are allowed. The reason is :
The only possible solution is
2,3,5
11 19
7 13
23 37
From this it can be observed that to get a multiple of 10 (i.e. 100) the only possible combination after 2,3,5 is numbers ending with 1 & 9 or 3 & 7
Even if all the smallest numbers are taken (to meet the second condition of 8 prime numbers) the closest sum you can get is 90.
Which means you are dependent on 2,3 &5 to reach the final sum.
Let me know if there is a better explanation.
Post a Comment
Links to this post:
Create a Link
<< Home