Question 1114679
<pre>
              SPEED            TIME           DISTANCE

M to S         r-70            {{{1485/(r-70)}}}      1485       

S to M         r+60            {{{1485/(r+60)}}}      1485

TOTAL                        {{{7&1/6}}}
</pre>

Manila to Singapore - headwind
Singapore to Manila - tailwind


Solve the equation for sum of the times,  {{{1485/(r-70)+1485/(r+60)=7&1/6}}}.