Gorilla fruit supply

At the Prague Zoo, they need to know how long the fruit will last for the gorillas. The stock in the warehouse would last the female Kamba for 25 days, the male Richard for 20 days, and the little Nura even for 40 days. How long will the supply last if everyone is fed from it?

Final Answer:

t =  8.6957 d

Step-by-step explanation:

$$\begin{gathered} t_1=25\text{d} \\ {t}_2=20\text{d} \\ {t}_3=40\text{d} \\ d=1/t_1+1/t_2+1/t_3=1/25+1/20+1/40=\frac{23}{200}=0.1151\text{/d} \\ t=1/d=1/0.115=8.6957\text{d} \end{gathered}$$

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