Answer:
4.875 billion hours
Step-by-step explanation:
-Let X be the total time spent on taxes and 7.8 billion (80%) is time on paper work.
#We equate and cross multiply to get the total time on taxes:
[tex]0.8=7.8\\1=X\\\\\therefore X=\frac{1\times 7.8}{0.8}\\\\\\=9.75[/tex]
-let y be the 50% amount of time spent. we equate to find it in actual hours:
[tex]1=9.75\\0.5=y\\\\y=\frac{9.75\times 0.5}{1}\\\\=4.875[/tex]
Hence, 50% of the time is equivalent to 4.875 billion hours