#
Problem
of the Week

Problem
A and Solution

Delivery
Dilemma

## Problem

At the beginning of the day, a delivery truck contains \(368\) packages.

The driver of the truck is making deliveries to various office buildings
in a city.

Between \(9\) a.m. and \(10\) a.m., they deliver \(66\) packages.

Between \(10\) a.m. and \(11\) a.m., they deliver \(103\) packages.

Between \(11\) a.m. and \(12\) p.m., they deliver \(88\) packages.

When the drivers returns to the depot for a lunch break, \(273\) packages are added to the truck.

Between \(1\) p.m. and \(2\) p.m., they deliver \(111\) packages.

Between \(2\) p.m. and \(3\) p.m., they deliver \(86\) packages.

At \(4\) p.m., they have \(99\) packages left in the truck. How many
packages did they deliver between \(3\)
p.m. and \(4\) p.m.?

## Solution

Since they start with \(368\)
packages in the truck, at \(10\) a.m.
they will have \(368 - 66 =
302\) packages in the truck.

Then at \(11\) a.m. they will have
\(302 - 103 = 199\) packages in the
truck, and at \(12\) p.m. they will
have \(199 - 88 = 111\) packages in the
truck.

At lunch they add \(273\) packages
to the truck, so there are now \(111 + 273 =
384\) packages in the truck.

Thus, in the afternoon, they start with \(384\) packages in the truck.

Then at \(2\) p.m. they will have \(384 - 111 = 273\) packages in the truck,
and at \(3\) p.m. they will have \(273 - 86 = 187\) packages in the truck.

Since there are \(99\) packages on
the truck at \(4\) p.m., then there
must have been \(187 - 99 =
88\) packages delivered between \(3\) p.m. and \(4\) p.m.