Answer:
she spend $600 more on phone than on bag.
part A:
let the money she have be m,
she spent on mobile phone:
→
remaining:
→

she spent on bag:
→

remaining:
→

so,
= 60
m = $900
part B:
money she spent on mobile phone:
→
→ $720
money she spent on bag:
→
→ $120
more money she spent on mobile phone than on bag:
mobile phone cost - bag cost
720 - 120
$600