Area of 1" sensor is ~65% bigger.
(some possible variation depending on aspect ratios)
Back to primary school to learn math.
Or then decide it has just not so "media sexy" 12MP.
With far more (marketing) pixels in notably smaller sensor pixel size is far smaller...
And with fixed size of "support circuitry" actual light gathering area has smaller percentage of that at least without backside illumination. (though better micro lenses can mitigate some of that)
Hence per pixel quality is standard crappy with not much light gathered and limited dynamic range from fast saturation of tiny photosite.
Achieving real quality needs binning 2x2 pixels to one to average noise at quarter the resolution.
Or every other row can be read earlier/at shorter exposure to avoid saturation and increase dynamic range.
But Quad Bayer sensor also means actual colour resolution is far lower than 48MP, because colour data is only gotten in 2x2 pixel chunks.
Quad Bayer and Quad Pixel AF are two very similar technologies with utterly different impact on the cameras that use them. Find out what OM Digital Solutions is doing with its OM-1 and learn about the secret behind two of the best video ILCs on the market.
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F2 collects twice the light of f2.8.
F1.7 goes another half "stop" further. (full doubling at f1.4)
That makes three times the light. (per same exposure time)
Though resolution wise optical quality demands go up like exponentially at those apertures and there's no stopping down to lower resolution decreasing effect of optical aberrations.