



 
Hi Eshraj, I am going to show you how to get started on a similar question.
Let the unknown whole number be $n$ then the previous whole number is $n  1.$ The first sentence of the problem mentions two fifths of the whole number so that's $\large \frac25 n.$ Also one half of the previous whole number is $\large \frac12 (n  1)$ so one less than one half of the previous whole number is $\large \frac12 (n  1)  1.$ Hence "Two fifths of a whole number is one less than one half of the previous whole number." becomes the equation \[\frac25 n = \frac12 (n  1)  1\] Solve for $n.$ Now try your problem and write back if you need more help,  


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