} Ritangle - an Integral maths competition
21 days...
21 questions...
leading to one answer...
and one winning team.

Corrections, clarifications and advice for Ritangle 2019

1. The first version of question 10 which appeared on the site contained a small error. The version which appeared at 1310 on 18th November 2019 is correct.

The sentence "For example, since π = 3.1415926536…., π-time is the 3rd day of January, 4159, 26 seconds and five minutes past 3am (so no rounding)." replaced the original sentence which read "For example, since π = 3.141592654…., π-time is the 3rd day of January, 4159, 26 seconds and five minutes past 4am."

2. Be careful to follow the instructions exactly to get the ‘final answer’ for each question.

For example, suppose the question was

Find, to three significant figures, the length of the hypotenuse of a right-angled triangle whose other sides both have length 1.
To get your final answer, take your value, multiply it by 943, add 2, and take the integer part.


Your working to get the final answer would be as follows.
The length of the hypotenuse is the square root of 2.
This is 1.41 to three significant figures.
This is the value you need to “multiply by 943, add 2, and take the integer part”.
(1.41 x 943) + 2 = 1331.63 (to 2 d.p.).
The integer part of this is 1331. So this is your final answer for this question.

3. Units of measurement are only used in Ritangle questions when they are particularly relevant to the context of the question.

When units are used you may need to take that into account in arriving at your final answer. Final answers are always entirely numerical and never include units.