Answer:
=
+
+
Step-by-step explanation:
=multiple ways to climb a tower
When n = 1,
tower= 1 cm
= 1
When n = 2,
tower =2 cm
= 2
When n = 3,
tower = 3 cm
it can be build if we use three 1 cm blocks
= 3
When n = 4,
tower= 4 cm
it can be build if we use four 1 cm blocks
= 6
When n > 5
tower height > 4 cm
so we can use 1 cm, 2 cm and 4 cm blocks
so in that case if our last move is 1 cm block then will be
n —1 cm
if our last move is 2 cm block then will be
n —2 cm
if our last move is 4 cm block then will be
n —4 cm
=
+
+