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Mice21 [21]
3 years ago
8

A man bought 42 stamps, some 13¢ and some 18¢. How many of each kind did he buy if the cost was $6.66?

Mathematics
1 answer:
OverLord2011 [107]3 years ago
5 0
Let's call the 13¢ stamps a and the 18¢ stamps b: a+b = 42 and therefore a= 42-b (formula 1) 0.13a+0.18b= 6.66 In this formula, substitute the value of a according to formula 1: 0.13(42-b)+0.18b= 6.66 Multiply on the left to get rid of the parenthesis: 5.46-0.13b+0.18b= 6.66 Subtract 5.46 from both sides: -0.13b+0.18b= 1.20 Add on the left: 0.05b= 1.20 Divide both sides by 0.05 b= 24 You have 24 18¢ stamps and: 42-24= 18 13¢ stamps Check: (24 x 0.18) + (18 x 0.13)= 6.66 Correct.
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Answer:

A. to make inferences about a sampling technique

Step-by-step explanation:


6 0
3 years ago
Wyatt offers 8 types of sandwiches and 4 types of tacos. He will increase his selection of sandwiches by 1 per month. He will in
Klio2033 [76]

Answer:

In 4 months Wyatt offer an equal number of sandwiches and tacos.

Step-by-step explanation:

We are given the following in the question:

Types of sandwiches = 8

Rate of increase of sandwich = 1 per month

Thus, number of sandwiches in x months will be given by

n_1(x) = 8 + x

Types of tacos = 4

Rate of increase of tacos sandwich = 2 per month

Thus, number of tacos in x months will be given by

n_2(x) = 4 + 2x

Equating the two equations, we get,

n_1(x) = n_2(x)\\8 + x = 4 + 2x\\\Rightarrow x = 4

Thus, in 4 months Wyatt offer an equal number of sandwiches and tacos.

4 0
4 years ago
What is 50 tens ×4 hundred = 40 tens × 5hundred true or false?
Vladimir79 [104]
True. 500x400=400x500
3 0
3 years ago
Ieda and Thanh both offer piano lessons. Ieda charges an initial fee of $8.50 and an hourly rate of $11.00. Thanh charges an ini
Trava [24]
The price for each instructor will be the same at 3 hours. How I determined this answer:

First off, you need to add the initial price and hourly price for each person together, so you already know how much it will cost for 1 hour, including the initial fee. Here's how you do it:

Ieda: $11.00 (hourly price) + $8.50 (initial fee) = $19.50 (for 1 hour)

Thanh: $10.50 (hourly price) + $10.00 (initial fee) = $20.50 (for 1 hour)

Now that you have the price for 1 hour including the initial fee, now you need to find the price for each hour after that. Here's how I did that:

I created a graph that looked like this:

Hours:       1                 2                  3               
Ieda:      19.50          30.50         41.50
Thanh:   20.50          31.00         41.50

Here's how I figured out the price for each hour:

Ieda:

Hour 1 (including initial price):
            $11.00 + $8.50 = $19.50
Hour 2 (excluding initial price): Only add the hourly price after Hour 1!
            $19.50 + $11.00 = $30.50 
Hour 3 (excluding initial price):
            $30.50 + $11.00 = $41.50

Thanh:

Hour 1 (including initial price):
            $10.50 + $10.00 = $20.50
Hour 2 (excluding initial price):
            $20.50 + $10.50 = $31.00
Hour 3 (excluding initial price):
            $31.00 + $10.50 = $41.50

So, looking at the graph, their prices are the same once each instruction reaches 3 hours. ($41.50)

I hope I was able to help you! :)
5 0
3 years ago
Read 2 more answers
Hey guys I need this fast. and please show step by step because I'm willing to give brainly
I am Lyosha [343]

Answer:

32

Step-by-step explanation:

3 0
3 years ago
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