Question

Intr-zi sa recoltat $\frac{1}{2}$ din suprafata cultivata, a doua zi $\frac{1}{3}$ din rest, a treia zi $\frac{1}{4}$ din noul  rest,iar a patra zi ultimele 10 hectare. Ce suprafata a fst cultivata?

Answer 1

x-suprafata recoltata
I zi : x-1/2·x=x-x/2=(2x-x)/2=x/2
II zi :  x/2-1/3·x/2=x/2-x/6=(6x-x)/6=5x/6
III zi: 5x/6-1/4·5x/6=(5x/6-5x/24=(20x-5x)/24=15x/24
15x/24=10
15x=10·24
x=240/15
x=16 ha supraf cultivata