5280 feet = 1 mile
31,680 feet = x miles
31,680/5,280 = 6
31,680 feet = 6 miles.
Your answer is A. 6.
Answer:
180 - 61 = 119
Step-by-step explanation:
So from A to D it is 180 degrees so just have to subtract 61 from 180 for an answer.
Given:
Cost to build a bookshelf = $20
Cost to build a table = $45
Amount available to spend = $600
Let x = number of bookshelves built.
Let y = number of tables built.
The total number of bookshelves and tables = 18.
Therefore
x + y = 18.
That is,
y = 18 - x (1)
The total amount available to build x bookshelves and y tables = $600. Therefore
20x + 45y = 600
That is (dividing through by 5),
4x + 9y = 120 (2)
Substitute (1) into (2).
4x + 9(18 - x) = 120
4x + 162 - 9x = 120
-5x = -42
x = 8.4
From (1),obtain
y = 18 - 8.4 = 9.6
Because we cannot have fractional bookshelves and tables, we shall test values of x=8, 9 and y=9,10 for profit
Note: The profit is $60 per bookshelf and $100 per table.
If x = 8, then y = 18-8 = 10.
The profit = 8*60 + 10*100 = $1480
If x = 9, then y = 18-9 = 9.
The profit = 9*60 + 9*100 = $1440
The choice of 8 bookshelves and 10 tables is more profitable.
Answer: 8 bookshelves and 10 tables.
Decibel is directly proportional to number of cars passing the point. That is,
69 db ----- 139 cars
x db ----- 17 cars
x = number of cars passing the point per minute on a weekend.
Then,
x= (69*17)/139 = 8.43 db ≈ 8 db
Answer:


Step-by-step explanation:
If the rate is x, then the rate of the return is x+25. In both trips, he has 40 miles to travel, therefore, it will take 40/x hours in the first trip and 40/x+25 for the return. As a consecuence

Also,

This means that if he starts at 30 miles per hour, it will take a bit more than 1 hour to be there: 1 hour and 20 minutes in the first trip, and a bit more than 40 minutes (40/55 hours) in the return.