Answer:
T=180minutes or 3 Hours
Step-by-step explanation:
Given the teacher was able to grade 3/4 of the class papers in 2hours and 15 minutes. Let there be x number of children in the class. Now convert the time into one unit ie, minutes .
1 hour=60 minutes
2 hours=120 minutes.
total time taken by the teacher to grade 3/4 of the class papers is=120+15=135minutes.
Now
3/4 of the class papers graded in 135 minutes.
let the time taken to grade all the papers is T; then
[tex]3/4x--->135[/tex]
[tex]x--->T[/tex]
On cross multiplication we get
[tex]135*x=T*(3x/4)[/tex]
[tex]T=135*4/3[/tex]
[tex]T=180[/tex] minutes.
Therefore the total time taken by the teacher to grade all the papers in the class is 180 minutes or 3 Hours.
