Monthly maths problem from RTSdécouverte - Increase or decrease?

Wednesday, 19 June, 2019

We invite you to solve the English version of the  RTSdécouverte monthly problem:


Increase or decrease?

This month, we're testing your intuition about percentages.

Over ten years, the workforce increased by 20%. Over the same period the percentage of unemployed rose from 9% to 8%.

Has the number of unemployed decreased or increased in ten years?

Over a thirty year period, the price of coffee successively increased by 30%, fell by 50% and then increased again by 40%.

Overall, has the price decreased or increased and by how much?

Original RTS Problèmes du mois (FR)

From 100 énigmes mathématiques de tous les jours, Michel Soufflet, Vuibert, Paris, 2014.

Photo credits our member: Nikita Nikolaev