There deals are available at a fair.
Deal 1. Pay$10,rides cost $4 /each.
Deal 2. Pay $20, rides cost $1/each.
Deal 3. Pay$30.all rides are free.
a. Write an expression for the total cost of n rides using deal 1. (The total cost includes the entry fee of $10.)
b. Write an expression for the total cost of n rides using deal 2.
c.Write an expression for the total cost of n rides using deal 3.
d. Which of the three deals is best for someone going on just two rides?
e. Which of the three deals is best for someone going on 20 rides?
f. Fill in the gaps:
i Deal 1 is best for people wanting up to ----- rides.
ii. Deal2 is best for people wanting between----- and ---- rides.
iii. Deal 3 is best for people wanting more than ------ rides.
請 將 每 問 題 笞 案 計 算 過 程 寫 出 .謝
math F.1
2012-10-13 10:58 am
回答 (1)
2012-10-13 3:36 pm
✔ 最佳答案
a. total cost = T1 = 10 + 4nb. total cost = T2 = 20 + n
c. total cost = T3 = 30
d. when n=2,
T1 = 10 + 8 = 18
T2 = 20 + 2 = 22
T3 = 30
therefore, deal 1 is the best (as T1 is the least cost)
e. when n=20, T1=90, T2=40, T3=30
therefore, deal 3 is the best.
f.
i. Deal 1 ... 3 rides
ii. Deal 2 ... 4 and 10
iii Deal 3 ... 10
(in fact, when n=10, deal 2 and deal 3 are equally best.)
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