Bill is 30 years older than Tom. In 5 years, Bill will be 4 times as old as Tom.

let bill age be x

so tom will be x-30

after 5 years wbill age will be x+5 and tom will be x-25

according to qusetion

bill age will be 4 times dat of tom after 5 yrs

=>x+5 =  4*(x-25)

=> x + 5 = 4x - 100

=> 3x = 105

=> x = 35

thus tom age = 35 -30 =5(answer)