Question 297242
Let {{{b}}} = your speed riding your bike
Then, your speed walking is {{{(1/4)*b}}}
In words:
(time spent walking and biking) = (distance biking/biking speed) + (distance walking/walking speed)
{{{3 = 8/b + 4/((1/4)*b)}}}
Multiply both sides by {{{(1/4)*b}}}
{{{(3/4)*b = 2 + 4}}}
{{{3b = 4*6}}}
{{{b = 8}}}
The speed biking is 8 mi/hr
check:
{{{3 = 8/b + 4/((1/4)*b)}}}
{{{3 = 8/8 + 4/((1/4)*8)}}}
{{{3 = 1 + 4/2}}}
{{{3 = 3}}}
OK