Question 387664
Rate*Time=Distance
{{{R*t=D}}}
.
.
{{{R[e]*t=150}}}
{{{t=150/R[e]}}}
.
.
{{{R[f]*t=100}}}
{{{t=100/R[f]}}}
.
.
{{{150/R[e]=100/R[f]}}}
{{{100R[e]=150R[f]}}}
{{{R[e]=(150/100)R[f]}}}
{{{R[e]=(3/2)R[f]}}}
.
.
{{{R[e]=R[f]+20}}}
Substitute,
{{{(3/2)R[f]=R[f]+20}}}
{{{(1/2)R[f]=20}}}
{{{highlight(R[f]=40)}}}kph
.
.
{{{R[e]=(3/2)(40)}}}
{{{highlight(R[e]=60)}}}kph