Library / UKMT Junior Kangaroo /182 of 243

UKMT Junior Kangaroo, 2017

Geometry Difficulty 2.0 Junior Find the answer United Kingdom

Henna has four hair ribbons of width $10$ cm. When she measures them, she finds that each ribbon is $25$ cm longer than the next smallest ribbon. She then arranges the ribbons to form two different shapes as shown in the diagram. How much longer is the perimeter of the second shape than the perimeter of the first shape?

(A) $75$ cm (B) $50$ cm (C) $25$ cm (D) $20$ cm (E) $0$ cm

Figure for this problem

We don't reproduce this publisher's solutions. Their own solution is here — work the problem first.

Want a route through all this instead of an archive? The track puts 2,604 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: UK Mathematics Trust, licensed © UK Mathematics Trust; past papers published free at ukmt.org.uk. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.