SOLUTION: The ratio of robins to blackbirds that visit our feeder 4 to 7. If there are a total of 123 birds, how many robins visit the feeder? (show your work)

Algebra ->  Customizable Word Problem Solvers  -> Misc -> SOLUTION: The ratio of robins to blackbirds that visit our feeder 4 to 7. If there are a total of 123 birds, how many robins visit the feeder? (show your work)      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 42102: The ratio of robins to blackbirds that visit our feeder 4 to 7. If there are a total of 123 birds, how many robins visit the feeder? (show your work)
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
Let there be 'x' robbins and 'y' blackbirds.
As the ratio of robbins to blackbirds is 4:7, so
x%2Fy=4%2F7
or y=7x%2F4

Also total no. of birds = no. of robbins + no. of blackbirds = x + y = 123 (given).

Thus we have two unknowns (x & y) and two equations to solve.
y=7x%2F4 ______(1)
x%2By=123______(2)

Substituting the value of 'y' from (1) in (2),
x%2B7x%2F4=123
or 11x%2F4+=+123
or x=123%2A4%2F11
or x = a fraction.

The number of birds cannot be fraction they have to be positive integers.
So, your question has erroneous data.
Before putting your question, be careful about typing mistakes in future.