mscroggs.co.uk
mscroggs.co.uk

subscribe

# Sunday Afternoon Maths XVIII

Posted on 2014-06-22

## Seven digits

"I'm thinking of a number. I've squared it. I've squared the square. And I've multiplied the second square by the original number. So I now have a number of seven digits whose final digit is a 7," said Dr. Dingo to his daughter.
Can you work out Dr. Dingo's number?
Tags: numbers

## Parabola

On a graph of $$y=x^2$$, two lines are drawn at $$x=a$$ and $$x=-b$$ (for $$a,b>0$$. The points where these lines intersect the parabola are connected.
What is the y-coordinate of the point where this line intersects the y-axis?
If you enjoyed these puzzles, check out Advent calendar 2019,
puzzles about circles, or a random puzzle.

## Archive

Show me a random puzzle
▼ show ▼