To solve this problem you must apply the proccedure shown below:
1. Calculate the number of problems finished by Tan, as following:
[tex] (45problems)(\frac{3}{5} )=27 problems [/tex]
2. Calculate the number of problems that he has not finished:
[tex] 45 problems-27problems=18problems [/tex]
3. If each problem finished took him [tex] 1^{\frac{4}{5}} minutes =1.8 minutes [/tex], you have that the rest of problem will take him:
[tex] (18 problems)(1.8minutes)=32minutes [/tex]
The answer is: [tex] 32 minutes [/tex]
