Answer:
$21
Step-by-step explanation:
Provided total value = $50
$50 = 5,000 cents.
We are provided,
10 cent coins value = 30% of total value
= 0.3 5,000 cents = 1,500 cents
Value of 20 cents coin = 28% of total value
= 0.28 5,000 cents = 1,400 cents
Therefore, remaining value of cents = Total value of 50 cents coins
5,000 cents - value of 10-cent coins - value of 20-cent coins = total value of 50 cents coins
5,000 - 1,500 - 1,400 = 2,100 cents = $21
Which means number of 50 cents coin =
Alternatively,
To calculate value of 50 cent coins
Total value = 100%
Value in 10-cent coins + 20-cent coins = 30% + 28% = 58%
Value in 50-cent coins = 100 - 58 = 42%
= $50 42% = $21
There is a mandatory fixed rate of $ 35 that Raphael will have to pay once the service call has been made. This fixed rate is the constant.
The per hour rate is $20. Suppose the machine took "x" hours to get fixed. Then the variable part of the repair cost will be .
Thus, Repair Cost=Fixed Rate Cost+Variable Cost
Or, where
is the total repair cost. Thus, if Raphael ‘s machine took 2 hour to fix, the repair cost is:
dollars.
Therefore, the last option is the correct option.