Question

there is a verandah 40 m long and 15 m broad it should be paved with stone of length 5 by 6 decimeter find no of stones needed

Answer 1

For verandah:
Length=40m=400dm.
Breadth=15m=150dm.
Area=400*150=60000dm^

For stone:
Length=6dm
Breadth=5dm
Area=6*5=30dm^

Total no. of stones needed to pave the verandah=
                                           =Area of verandah / area of each stone.
                                           =60000dm^ / 30dm^
                                           =2000.