Finding numbers

Question

one number is 5 times a first number. a third number is 100 times more than the first number. if the sum of the three numbers is 408, find the numbers.

Answer 1

Let the three numbers be F,S and T for first, second and third

S=5F

T=100+F

F+S+T=408

substitute to get an equation with just F a the variable

F+5F+F+100=408.

7F = 308

F = 308/7 = 44

S=5(44) = 220

T=44+100 = 144

44+220+144 = 408