Answer:
Part 1:
Let the nickels be = n
Let the dimes be = d
Let the quarters be = q
Plato has 36 coins in nickels, dimes, and quarters. So, equation forms:
.....(1)
The number of nickels is three less than twice the number of dimes.
....(2)
The total value of the coins is $5.20.
.... (3)
Substituting n=2d-3 in (1) and (3)
=> ....(4)
=>
=> ...(5)
Multiplying (4) by 0.25 and subtracting (5) from (4)
now subtracting (5) from this we get;
=> d = 8
Substituting d = 8 in
=> q = 15
Substituting values of d and q in , we get n
=> n = 13
Therefore Plato has 13 nickels, 15 quarters and 8 dimes.
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Part 2:
Let the original price of the ski hat be = x
Original price was marked down by 35% means value was lowered by 35%.
So, we can calculate as:
=>
=>
x = 24
Hence, the original price was $24 but after 35% marking down, it was available for $15.60.