Question 1169606
"It takes 3 and__hours both pipes to fill up the same tank."
Not absolutely clear, but assuming that might be three and one half hours, then,...


<pre>
PIPE              FILL RATES

A Certain         {{{1/y}}}

Another           {{{1/(y+2)}}}

BOTH TOGETHER     {{{1/(3&1/2)}}}
</pre>


{{{1/y+1/(y+2)=1/(3&1/2)}}}-------question asks for y.
.
.
... ,  {{{y=6.14*hours}}}