Given that height of each book is 3cm 5mm
We need to find the height of a pile of 25 books in meters
1cm = 10mm
so 3cm = 30cm
3 cm 5 mm = 30 mm + 5 mm
= 35 mm
The height of a pile of 25 books is
25 X 35
= 875 mm
We will convert into meters
1 mm = 0.001 m
875 mm = 0.001 X 875 m
=0.875 m
Height of 25 pile of books is 0.875 m where the height of one book is 3cm and 5mm