CHECK YOUR BRAIN
<pre class="tw-data-text vk_txt tw-ta tw-text-small" data-placeholder="Translation" id="tw-target-text" data-fulltext="" dir="ltr" style="unicode-bidi: isolate; font-family: inherit; border: none; padding: 0px 0.14em 0px 0px; position: relative; margin-bottom: 0px; resize: none; overflow: hidden; width: 237.5px; white-space: pre-wrap; color: rgb(33, 33, 33); height: 96px; font-size: 16px !important; line-height: 24px !important; background-color: rgb(255, 255, 255);">There are a few ducks and goats in a field . Overall, 77 heads and 224 feet . What is the number of ducks ?</pre>

It depends on how many 3-legged goats and one-legged ducks there are.&nbsp;

duck = xgoat = yx + y = 77-------&gt; x = 77 - y2x + 4y = 224 -----&gt; simplified --------&gt; x + 2y = 112(77 - y) + 2y = 11277 - y + 2y = 112y = 112 - 77&nbsp;y = 35 so, x = 77 - yx = 77 - 35 = 4242 ducks

Let's all goats and &nbsp;ducks raise two feet. So 224-77*2 feet left, that's 70 feet. All goats fall down. Each ducks left 2 feet on ground. So there are half of 70 ducks, that's 35.

Ne manquez pas cette occasion d'apprendre une langue depuis chez vous. Découvrez notre sélection de professeurs de langues expérimentés et inscrivez-vous dès maintenant à votre premier cours !