IMO DGiven Information:
Warren has three types of coins: $0.25, $0.50, and $1.
Number of $0.25 coins = 8
Number of $0.50 coins = 4
Statement (1):
The total value of the $1 coins in the piggy bank is 50% of the total value of all the coins.
Let's denote:
The number of $1 coins as
x
x.
Calculate the total value of the coins:
Value of $0.25 coins:
8
×
0.25
=
2
8×0.25=2 dollars
Value of $0.50 coins:
4
×
0.50
=
2
4×0.50=2 dollars
Value of $1 coins:
x
×
1
=
x
x×1=x dollars
Total value of all coins:
2
+
2
+
x
=
4
+
x
2+2+x=4+x
According to statement (1), the value of $1 coins is 50% of the total value:
x
=
0.5
×
(
4
+
x
)
x=0.5×(4+x)
Solving for
x
x:
x
=
2
+
0.5
x
x=2+0.5x
x
−
0.5
x
=
2
x−0.5x=2
0.5
x
=
2
0.5x=2
x
=
4
x=4
So, Warren has 4 $1 coins.
Statement (2):
The $1 coins make up 25% of the total number of coins in the piggy bank.
Let's denote:
The number of $1 coins as
x
x.
Calculate the total number of coins:
Number of $0.25 coins: 8
Number of $0.50 coins: 4
Number of $1 coins:
x
x
Total number of coins:
8
+
4
+
x
=
12
+
x
8+4+x=12+x
According to statement (2), the $1 coins make up 25% of the total number of coins:
x
=
0.25
×
(
12
+
x
)
x=0.25×(12+x)
Solving for
x
x:
x
=
3
+
0.25
x
x=3+0.25x
x
−
0.25
x
=
3
x−0.25x=3
0.75
x
=
3
0.75x=3
x
=
4
x=4
So, Warren has 4 $1 coins.
Conclusion:
Both statements (1) and (2) independently lead us to the conclusion that Warren has 4 $1 coins in his piggy bank.