- Each letter stands for a digit. All identical letters represent the same
digit. Find the solution.
PQ
þ Q
QP
- The sum of the digits of a two-digit number is 5. If 9 is subtracted
from the number, the answer will be the original number with the
digits reversed. - A person purchased 10 stamps of two denominations, $0.25 and
$0.15. How many of each kind did the person purchase if the total
is $2.10? - An 87-inch stick is broken into two pieces such that one piece is twice
as long as the other. Find the length of each piece. - How many ways can a committee of three people be selected from
four people? - Mortimer wants to shape up for football. He decides to cut back
by eating two fewer candy bars each day for five days. During the
five days, he ate a total of 30 candy bars. How many did he eat on the
first day? - A father is three times as old as his son. In 12 years, he will be twice
as old as his son. Find their present ages. - How many ways can 5 people line up in a row for a photograph?
- Find the tallest person if Betty is shorter than Jan, Sue is taller than
Betty, and Jan is shorter than Sue.
SOLUTIONS:
- Strategy: Draw a picture. Four cuts are needed. See Figure 21-3.
Fig. 21-3.
LESSON 21 Using Other Strategies 265