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a parking meter accepts only 20p coins or 50p coins.On one day, 39 coins were collected with a total value of $11.40. find how many 50p coins were collected.​

Respuesta :

RealGiveaway

Answer:

x + Y = 39 or x = 39-y

20x + 50y = 1.40

20 (39 - y) + 50y = 11.40

7.80 - 20y + 50y = 11.40

30y = 11.40 - 7.80

30y = 3.60

y = 3.60/30

y = 12 50p coins were collected.

x = 39 - 12 = 27 20p coins were collected.

Proof:

20*27 + 50*12 = 11.40

5.40 + 6 = 11.40

11.40 = 11.40

I hope it helps.

sqdancefan

Answer:

  12 50p coins were collected

Step-by-step explanation:

Let x represent the number of 50p coins. Then 39-x is the number of 20p coins. The total value of coins collected was ...

  20(39-x) +50(x) = 1140

  780 +30x = 1140 . . . . . . . simplify

  30x = 360 . . . . . . . . subtract 780

  x = 12 . . . . . . . . . divide by 30

12 of the 50p coins were collected.

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39 -12 = 27 of the 20p coins were collected.

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