there are 4 members in a family . their average income is rs . 10000 per month . 3 members get rs . 8000 , rs . 15000 , rs . 6000 respectively . therefore what is the income of the fourth member of the family ? Choose the correct option.
A) rs . 10000  B) rs . 11000  C) rs . 12000  D) rs . 9000  E) rs . 8500

Rationale: explanation total income of 3 members = rs . ( 8000 + 15000 + 6000 ) = rs . 29000 . required income = rs . [ ( 10000 x 4 ) – 29000 ] = rs . ( 40000 – 29000 ) = rs . 11000 . answer b
Answer: B