Question 1170294
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If a formal algebraic solution is not required, here is a quick and easy way to get the solution to a problem like this.<br>
(1) If all 35 animals were ducks, the number of feet would be 35*2 = 70.
(2) The actual total number of feet is 106, which is 36 more than 70.
(3) Each goat has 2 more feet than each duck.
(4) The number of goats needed to get the additional 36 feet is 36/2 = 18.
(5) Since the number of goats is 18, the number of ducks is 35-18 = 17.<br>
And of course you could do the same kind of solution starting by knowing that if all 35 animals were goats the number of feet would be 35*4 = 140.<br>