Let the overhead charges be 'x'
C.P of toys is Rs.75000
With overheads it becomes 75000+x Rs
S.P=(C.P+Overheads)+ Profit
Profit
= 0.1*(C.P+Overheads)
= 0.1*(75000+x) rs
Given that profit is 9000 rs
=> 0.1(75000+x) = 9000
=> 75000+x = 9000/0.1
=> 75000+x = 90000
=> x = 90000 - 75000
=> x = 15000 rs