Page 168 - NUMINO Challenge_D2

Problem solving 3 First, find the increased price and the discount

1 Let represents the number of hits for player price for each store.
Store A: 20% increase on the $20 bag $24
A. Then 0.375 40 , and 15. Let 10% increase on the $24 bag $26.40.
represent the number of hits for player B. Then Store B: 25% discount on the $40 bag $30
An extra 15% discount on the $30 bag $25.5.
0.375 48 and 18. Therefore, player B had Therefore, Sarah should go to store B, because
more base hits. she can get it for 90 cents less.

2 Since Batting Average Number of Hits ,
Number of Times at Bat

let represent the number of hits Bill made.

Then 0.28 21 , and 75. Therefore, Bill hit 4 First, find the number of hits for both players.

75 times. Since Number of Hits (Batting Average),
Number of Times at Bat

Creative Thinking p.126~p.127 the number of hits for Marc is 32 0.25.

Therefore, =8, and the number of hits for

1 Before the number of people changes, let a Josh is 36 0.25, therefore 9.
Since there was 1 hit in 5 at bat in the game both
represent the number of people in village A and

b represent the number of people in village B. players played, Marc made 9 hits in 37 at bat and

Since the number of people in village A Josh made 10 hits in 41 at bat. Therefore, the

increased by 20%, a 0.2 a 1.2 a. Since the batting average for Marc is 9 0.2432
37
number of people in village B decreased by
The batting average for Josh is 10 0.2439
10%, b 0.1 b 0.9 b. a is 3 of b; 41
4
therefore, the number of people in village A was

3 100 75% of the people in village B. 15 Thinking Backwards p.128~p.129
4

2 Since the first computer was sold for $750, Try It Again 60, 60, 180

which was 50% more than the original price, its Amount of Water
original price was $500. Since the second
computer was sold for $750, which was 50% less Dish A Dish B
than the original price, its original price was
$1,500. The sum of the original prices of the two 120 120
computers was $500 $1,500 $2,000. Lisa's
dad sold them for $750 $750 $1,500; 180(120 60) 60(120 2)
therefore, he had a loss of 2,000 1,500 500
dollars. 90(180 2) 150(60 90)

165(90 75) 75(150 2)

165, 75

Example 3, 3, 6 6, 8, 16
16, 18, 36

Answer Key