Reader\'s Digest India - 09.2019

158 september 2019

Skyscrapers
Difficult This grid represents a
bird’s-eye view of a city’s down-
town core. Place a number from
1 to 5 (representing a building’s
height in storeys) in each cell so
that no two buildings in any row or
column have the same height. The
numbers along the periphery tell
you how many buildings are visible
in a row or column to an observer
standing outside the grid and look-
ing in from the direction indicated
by the arrow. Higher buildings
block the view of lower ones
behind them. Can you determine
the heights of all 25 buildings?

Forest for the Trees
Moderately difficult
A spanning tree (or
just a tree, for short)
is a diagram made
of dots and straight
lines, where every
line goes between
two dots, where all
the dots are connec-
ted and where there
are no paths that go
around in a loop.

Here are some examples:

A drawing that has several spanning trees is called

a forest. If a forest has three trees and 27 lines in it,

how many dots does it have?

23

3

4

4

3

23

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