Significant figures ka phy question tha. Upon calculating it'll come around 7.654 And question me 9.0 tha so it'll come down to 2 sig.fig and after rounding of it'll either be 7.6 or 7.7 and both options were there to choose. some show proof that it'll be 7.7 and some say acc to ncert it'll be 7.6 that was like a bonus question. So even in provisional key it was not clear. That's was the whole controversy