Charlotte has a total of 23 nickels and dimes worth $1.85. how many of each type of coin does she have

Charlotte has a total of 23 nickels and dimes worth $1.85.

Let us assume  

Number of nickels = n

Number of dimes =d  

Total number of coins = 23

so n + d= 23

Now nickels and dimes worth $1.85.

We know that 1 nickel = 5 cents and 1 dime = 10 cents

convert $1.85 in to cents . $1.85 = 185 cents

5 n + 10 d = 185

Now we solve both the equations

n + d= 23 => n = 23-d

Replace n with 23-d in the second equation

5 (23- d) + 10 d = 185

115 - 5d +10 d = 185

Add like terms

115 + 5d = 185

Subtract 115 from both sides

5d = 70

Divide both sides by 5

so d = 14

n   = 23 - d

Replace 14 for d

n = 23 - 14 = 9

The number of nickels = 9

Number of dimes = 14

the answer is 288..

hope this

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

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x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

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x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

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x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!