Explanation:
4 days 6 hours = 4×24 + 6 = 102 hours
so, it consumes
7650 wh in 102 h.
or as ratio :
7650wh/102h
to find how many wh it consumes in a day (= 24h), we need to bring the denominator of the ratio fraction to 24.
and then multiply the numerator with the same factor, so that the overall fraction value is maintained.
102×f = 24
f = 24/102 = 12/51
so, now we know, to get our answer we need to do
7650/102 × (12/51 / 12/51) = (7650 × 12/51) / (102 × 12/51) =
= 1800/24
the light bulb consumes 1800 watt-hours per day.
FYI :
in 1 hour it consumes
(1800/24) / (24/24) = 75 watt-hours.
in other words, it is a 75 watt light bulb.