✅ Quick Answer

The number is 5.

🧠 Step-by-step breakdown

We take the fractions one at a time:

  1. One ninth of 900
    900÷9=100900\div 9=100900÷9=100

  2. One fourth of 100
    100÷4=25100\div 4=25100÷4=25

  3. One fifth of 25
    25÷5=525\div 5=525÷5=5

🔍 Shortcut method

You can combine everything into one step:

900×19×14×15=9009⋅4⋅5=900180=5900\times \frac{1}{9}\times \frac{1}{4}\times \frac{1}{5}=\frac{900}{9\cdot 4\cdot 5}=\frac{900}{180}=5900×91​×41​×51​=9⋅4⋅5900​=180900​=5

✅ Final result

5