Building a fence

This task is about multiplying with decimals.
To build a fence across their section Toni needed fence posts, lengths of timber, and palings.
 

illustration: person kneeling with hammer

a) Calculate the total length of ...
 
 
i)
 
ii)
 
iii)
4 fence posts, each 2.1 m long. __________ metres
 
6 lengths of timber, each 2.4 m long. __________ metres
 
46 palings, each 1.3 m long. __________ metres
 
b)
Palings cost $1.25 each.
 
How much would 46 palings cost? $ __________ . __________