Did you solve it? Turn it up to 11

Earlier today I set you the following two puzzles: 1) Why is every even digit palindrome divisible by 11? (An even digit palindrome is a palindromic number that contains an even number of digits, like 1221, or 678876.) Solution There are different ways to solve this one. My method is perhaps the least technical, but…

Can you solve it? Turn it up to 11

Legs eleven, Ocean’s Eleven, elevenses! Yes, let’s hear it for the number 11, star protagonist of today’s puzzles. Eleven is the first number you reach once you go beyond ten. Since ten is the base of our number system, eleven’s position gives it some interesting properties – as the members of Spinal Tap knew all…

Ruth Rogers obituary

My friend and colleague Ruth Rogers, who has died aged 91, was a mathematician deeply involved with solving important engineering problems. Her main area of interest was in fluid mechanics, and in particular rotating fluids – a meeting point between engineering and meteorology. It was here that Ruth was able to make some of her…