Question 718798
One way is to examine the first length and the second length and treat their sum.


First length: {{{R*1}}} kilometers.
Second length: {{{(R+1.5)(3/4)}}} kilometers.


First length plus second length is 22 kilometers.
{{{R+(R+1.5)(3/4)=22}}} and solve for R from this.  R is the slower runners speed.


{{{R+(3/4)R+1.5(3/4)=22}}}
{{{(1+3/4)R+9/8=22}}}
 {{{(7/4)R=22-9/8}}}
{{{R=(22-9/8)(4/7)}}}
{{{R=(20&7/8)(4/7)}}}
{{{R=(167/8)(4/7)}}}
{{{R=167/14}}}, {{{R=11.9}}}
Final Answer: R=12 kilometers per hour.