Answer:Andrew spent 2 2/3 hours studying in all
Explanation:
hours spent studying for his science exam=s 1 1/6 hours
hours spent studying for his history exam= 1 1/2
Total hours spent studying both subjects =1 1/6 hours+1 1/2 hours
add whole numbers to whole numbers and fraction to fraction
1 1/6 hours+1 1/2 hours
=2 1+3 /6
=2 4/6 =2 2/3 hours