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# KCC's Quizzes: Anniversary and Ages in Prime Numbers

In 1979, a mother and her 4 sons are aged 97, 67, 61, 59 and 53 respectively. All these ages and that year are prime numbers.

Questions:

1. That “situation” did already happen (prime numbers in the year and in their 5 ages) in the past for that family. When and what were their ages?
2. That “situation” can occur again in the future (we suppose science will allow us to live much longer than now). When and what will be their ages?
• A funny one, this quiz!

• 1. Yes, 30 years earlier in 1949 when they were 23,29,31,37,67

I'm still going on the second part...

• Phew, thank goodness.

563, 569, 571, 577 and 607 in 2489!

• He he, stopped calculating when I reached year 10,000....

it happened before in the year 1949, ages 67 37 31 29 23

it will happen again, science permitting, in the years

3209, ages 1327 1297 1291 1289 1283

3539, ages 1657 1627 1621 1619 1613

4259, ages 2377 2347 2341 2339 2333

5939, ages 4057 4027 4021 4019 4013

• 2489 can be divided by 19

• This was brute force Excel (laptop is smoking...) I'm very interested if there's a scientific/maffs approach to this

• Agree with Rakph, 2489 is not prime...

• Dear Brainstormers,

Since, with EZ, feedback are visible, I will comment and publish the official right answer only one week after (just before the launch of the new quiz)!

• 1. 1949 (30 years earlier). Their ages were 67, 37, 31, 29 and 23 respectively.
2. 2009 (30 years after). Ages were 127, 97, 91, 89 and 83 respectively.

• 91 is not a prime. Sad.