6. There are 24 hours in a day and he spends 0.6 (60%) percent of it studying. You do 24x0.6= 14.4 this means that he spent 14.4 hours studying.
8. A dozen is 12 so you do 8.75x12= 105 for a dozen oranges.
9. 15.5x1.6= 24.8km
10. 1 year is divided into 4 quarters, each quarter is three months because 12 months divided by 4 is 3. That means she paid 18,800 in march since it’s the third month of the year, in another three months she would pay 18,800 again. Every 1 month she pays 6,266 because 18,800 divided by 3 is 6,266. Every 12 months (or year) she pays 75,200 because 18,800x4= 75,200.
11. Every month he makes 8,000 and he saves 0.4 (40%) percent of it each month. 8,000x0.4=3,200 this means he saves 3,200 every month. Multiply 3,200 by 6 months and he saves 19,200 in 6 months.
(Didn’t do 7 and 12 sorry but hope this helped you understand better!)