Guess and Check Answers
In-class exercise #1:
1). 105
2). 10 bicycles
3). 4 porcupine posters and 2 giraffe posters. 4 x $7 + 2 x $5 = $28 + $10 = $38
In-class exercise #2:
1). Racket costs $35 and the balls cost $7 for a total of $42
2). They won 12 and lost 10 and tied 3 for a total of 25 rounds.
3). 275 girls and 238 boys for a total of 512 students
Practice competition #1 (Probability and Statistics):
1). mean=86.9, mode=88, median=88, range=25
2). 16/52 or (reduced) 4/13
3). Must add 6 green marbles. Then 5 + 9 + 4 = 18 and 9 is 1/2 of 18
4). 120 ways (5 x 4 x 3 x 2 x 1)
5). Area of field is 18 x 12 = 216 sq. ft. White areas are 6 x 4 + 16 - 1 = 39 sq. ft. 216 - 39 = 177 sq. ft. Probability is 177/216 which reduces to 59/72.
Practice competition #2 (Algebra):
1). Well, if 200 books are left, then there must have been 400 for half of them to be sold on the second day. On the first day 50 were sold, so they must have started with 450 books. The equation is (X - 50)/2 = 200; X - 50 = 400; X = 450.
2). X = 6
3). The equation is 9X + 45 = 192 - 3. So, 9X = 144 and X = $16.
4). Each result is the sum of the results of the previous number + the current number, so 7 + 21 = 28.
5). The equation is X + 3X + 4X = 180. So, 8X = 180 and X = 22.5o