Hi,
given the task description "your network team has configured half of the hosts on VLAN 36 to default to R3 and the other half to default to R6." I would suggest the following solution. The advantage is that with vrrp you can use the actual interface ip as standby IP.
R6:
interface FastEthernet0/0
vrrp 1 ip 141.1.36.3
vrrp 2 ip 141.1.36.6
R3:
interface FastEthernet0/1
vrrp 1 ip 141.1.36.3
vrrp 2 ip 141.1.36.6
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Rack1R6#sho vrrp brief
Interface Grp Pri Time Own Pre State Master addr Group addr
Fa0/0 1 100 3609 Y Backup 141.1.36.3 141.1.36.3
Fa0/0 2 255 3003 Y Y Master 141.1.36.6 141.1.36.6
Rack1R3#sho vrr brief
Interface Grp Pri Time Own Pre State Master addr Group addr
Fa0/1 1 255 3003 Y Y Master 141.1.36.3 141.1.36.3
Fa0/1 2 100 3609 Y Backup 141.1.36.6 141.1.36.6