Respuesta :

i believe it would be 4 1/5 hours
let me explain how you do this 
if for 1 day he studies 3/5s of an hour. And the question is asking for 7 days then all we have to do is multiply 3/5s times 7! Ill guide you through the math;)
 3                                                               3         7    
----   x   7  we can also write it like this   ---   x   ---   lets use this one:)  
 5                                                               5         1

but now our next step is to multiply across!
 
 3         7   =   3 x 7 = 21 
---   x  ----                       so our new fraction issssss
 5         1   =   5 x 1 = 5 

 21
-----   and since 5 goes into 21 four times and 2 is left over this is how         5     much he studied in 7 days  4.2 hours
or as a fraction...
    1
4 ----
    5
answer? 4.2 hours studied :D
have a good one and 
MARK ME BRAINLIEST!!:D
thxx bye