A mountain on a tropical island experiences changes in its height due to volcanic activity. Its current height is 5,181 meters, which is 10% taller than it was when the mountain was last measured. How tall was it then?

解

A m o u n t ain o n a t ro p i c a l i s l an d e x p er i e n ces c han g es in i t s h e i g h t d u e t o v o l c ani c a c t i v i t y . I t s c u rre n t h e i g h t i s 5, 181 m e t ers, w hi c h i s 10% t a ll er t han i t w a s w h e n t h e m o u n t ain w a s l a s t m e a s u re d . Ho w t a ll w a s i t t h e n ?

Amount before addition : 4710

解答ステップ

Translate the problem into an equation:

5181 = x + 0.1 x

5181 = x + 0.1 x : x = 4710

Amount before addition : 4710