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I REALLY NEED HELP!! I ONLY HAVE 20 MINUTES LEFT 

A collection of nickels and dimes is worth $2.95. There are 47 coins in all. How many nickels are there?

A.12

B.18

C.29

D.35



2 Answers

2 votes
n+d=47
5n+10d=295
divide 2nd by 5

n+2d=59


we have
n+d=47
n+2d=59
eliminate n
multiply first equaton by -1 and add to other equaton
-n-d=-47
n+2d=59 +
0n+1d=12

d=12
sub back

n+d=47
n+12=47
minus 12 both sides
n=35

35 nickles

D is answer
User Pavitar
by
8.0k points
3 votes

Answer: The correct option is (D) 35.

Step-by-step explanation: Given that a collection of nickels and dimes is worth $2.95 and there are total 47 coins.

We are to find the number of nickels.

We know that

1 nickel = $ 0.05 and 1 dime = $ 0.10.

Let, 'n' and 'd' represents the number of nickels and dimes in the collection.

Then, according to the given information, we have


n+d=47~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\\\\0.05n+0.10d=2.95\\\\\Rightarrow 5n+10d=295\\\\\Rightarrow n+2d=59~~~~~~~~~~~~~~~~~~~~~~~~(ii)

Subtracting equation (i) from equation (ii), we get


(n+2d)-(n+d)=59-47\\\\\Rightarrow d=12,

and from equation (i), we get


n+12=47\\\\\Rightarrow n=47-12\\\\\Rightarrow n=35.

therefore, there are 35 nickels in the collection.

Option (D) is correct.

User Petercopter
by
8.1k points