Pls with a clear explanation

Explanation:
We know that :
[tex]P = \frac{V^{2} }{R} [/tex]
Resistance of Bulb :
[tex]R = \frac{ V^{2} }{P } = \frac{ {(240)}^{2} }{280} = 205.71 \: ohms[/tex]
As per Ohms laws :
Current when (V = 200)
[tex]i \: = \frac{ V}{ R} = \frac{200}{205.71} = 0.97 \: A[/tex]