If x varies directly as y and x - 4 when y - 20- y when x - 12

Question

Toppr Admin · Accepted Answer

We know that x-x221D-y and x4 when y-20- Thus x-ky for some constant k- Putting x-4 and y-20 in this- we get 4-20k or k-1-5- HenceNow take x-12 in this- We obtain y-12-xD7-5-60-

If $x$ varies directly as $y$ and if $x = 4$ when $y = 20$ , find $y$ when $x = 12$

We know that $x \propto y$ and $x 4$ when $y = 20$ . Thus $x = k y$ for some constant $k$ . Putting $x = 4$ and $y = 20$ in this, we get $4 = 20 k$ or $k = 1 / 5$ . Hence
Now take $x = 12$ in this. We obtain $y = 12 \times 5 = 60$ .

If x varies directly as y and if x=4 when y=20, find y when x=12

We know that x∝y and x4 when y=20. Thus x=ky for some constant k. Putting x=4 and y=20 in this, we get 4=20k or k=1/5. HenceNow take x=12 in this. We obtain y=12×5=60.

If $x$ varies directly as $y$ and if $x = 4$ when $y = 20$ , find $y$ when $x = 12$

We know that $x \propto y$ and $x 4$ when $y = 20$ . Thus $x = k y$ for some constant $k$ . Putting $x = 4$ and $y = 20$ in this, we get $4 = 20 k$ or $k = 1 / 5$ . Hence
Now take $x = 12$ in this. We obtain $y = 12 \times 5 = 60$ .