4 5
M _ N _ T _ S .
M _ T H _ D
1
L _ T
_ S
T _ L K
_ B _ _ T
2 4
H _ _ R S
_ S
_ T
W _ L L
S _ M P L _ F Y
T H _
P R _ B L _ M .
I N
2 4
H _ _ R S :
T H _
C _ L D
T _ P
W _ L L
B _
_ B L _
T _
F _ L L
T H _
B _ T H T _ B
8 0
T _ M _ S .
T H _
H _ T
T _ P
W _ L L
B _
_ B L _
T _
F _ L L
T H _
B _ T H T _ B
9 6
T _ M _ S .
T H _
D R _ _ N
W _ L L
B _
_ B L _
T _
D R _ _ N
T H _
B _ T H T _ B
1 4 4
T _ M _ S .
T H _ S
_ N
2 4
H _ _ R S ,
T H _
B _ T H T _ B
W _ L L
B _
F _ L L _ D
8 0
+
9 6
-
1 4 4
=
3 2
T _ M _ S
( _ F
B _ T H
T _ P S
_ R _
T _ R N _ D
_ N
W _ T H
T H _
P L _ G
L _ F T
_ _ T )
T H _ S
_ T
W _ L L
T _ K _
4 5
M _ N _ T _ S
T _
F _ L L
T H _
T _ B
_ N C _ .
M _ T H _ D
2
T H _
B _ T H T _ B
F _ L L _ N G
R _ T _
_ S :
T H _
C _ L D
T _ P
W _ L L
F _ L L
T H _
B _ T H T _ B
_ T
1 / 1 8
T _ B / M _ N _ T _
T H _
H _ T
T _ P
W _ L L
F _ L L
T H _
B _ T H T _ B
_ T
1 / 1 5
T _ B / M _ N _ T _
T H _
D R _ _ N
W _ L L
D R _ _ N
T H _
B _ T H T _ B
_ T
1 / 1 0
T _ B / M _ N _ T _
T H _
N _ T T
B _ T H T _ B
F _ L L
R _ T _
_ S :
1 / 1 8
+
1 / 1 5
-
1 / 1 0
=
1 / 4 5
T _ B / M _ N _ T _
T H _
W _ T _ R
W _ L L
F _ L L
1 / 4 5
_ F
T H _
T _ B
_ N
1
M _ N _ T _ ,
S _
T H _
T _ B
W _ L L
B _
F _ L L
_ N
4 5
M _ N _ T _ S Clue
45 MINUTES. METHOD 1 LET US TALK ABOUT 24 HOURS AS IT WILL SIMPLIFY THE PROBLEM. IN 24 HOURS: THE COLD TAP WILL BE ABLE TO FILL THE BATHTUB 80 TIMES. THE HOT TAP WILL BE ABLE TO FILL THE BATHTUB 96 TIMES. THE DRAIN WILL BE ABLE TO DRAIN THE BATHTUB 144 TIMES. THUS IN 24 HOURS, THE BATHTUB WILL BE FILLED 80 + 96 - 144 = 32 TIMES (IF BOTH TAPS ARE TURNED ON WITH THE PLUG LEFT OUT) THUS IT WILL TAKE 45 MINUTES TO FILL THE TUB ONCE. METHOD 2 THE BATHTUB FILLING RATE IS: THE COLD TAP WILL FILL THE BATHTUB AT 1/18 TUB/MINUTE THE HOT TAP WILL FILL THE BATHTUB AT 1/15 TUB/MINUTE THE DRAIN WILL DRAIN THE BATHTUB AT 1/10 TUB/MINUTE THE NETT BATHTUB FILL RATE IS: 1/18 + 1/15 - 1/10 = 1/45 TUB/MINUTE THE WATER WILL FILL 1/45 OF THE TUB IN 1 MINUTE, SO THE TUB WILL BE FULL IN 45 MINUTES THE ADDRESS IS 1460 SUNSET BOULEVARD. YOU KNOW THAT THE HOUSE NUMBERS ARE EVEN AND CONSECUTIVE, SO THEY MUST BE APPROXIMATELY 1/6TH THE VALUE OF THE SUM 8790. IN FACT, THE NUMBER THAT IS 1/6TH THE TOTAL IS THE MEAN (AVERAGE) FOR ALL 6 HOUSES. THE AVERAGE NUMBER IS 1465 (8790 / 6). THERE MUST BE 3 HOUSE NUMBERS GREATER THAN THAT NUMBER, AND 3 HOUSE NUMBERS LESS THAN THAT NUMBER, ALL BEING EVEN AND CONSECUTIVE. THEREFORE, THE 6 HOUSE NUMBERS ARE 1460, 1462, 1464, 1466, 1468, 1470. THE LOWEST HOUSE NUMBER, AS PER THE QUESTION, IS THE ANSWER: 1460 A = 3.5 B = 4.5 C = 9.5 D = 3.5 TO SOLVE THE PUZZLE, YOU WILL NEED TO COME UP WITH 4 EQUATIONS: A + B = 8 ... (1) C - D = 6 ... (2) A + C = 13 ... (3) B + D = 8 ... (4) SUBTRACTING (1) FROM (3) GIVES: C - B = 5 ... (5) ADDING (2) TO (4) GIVES: B + C = 14 ... (6) ADDING (5) AND (6) GIVES: 2C = 19 C = 9.5 SUBSTITUTING C = 9.5 IN (2) GIVES: 9.5 - D = 6 D = 3.5 SUBSTITUTING D = 3.5 IN (4), GIVES: B + 3.5 = 8 B = 4.5 SUBSTITUTING B = 4.5 IN (1), GIVES: A + 4.5 = 8 A = 3.5 FOR THE TRAIN TO PASS COMPLETELY THROUGH THE TUNNEL, IT MUST TRAVEL 2 MILES. AFTER 1 MILE TRAVEL, THE TRAIN WOULD BE COMPLETELY IN THE TUNNEL, AND AFTER ANOTHER MILE IT WOULD BE COMPLETELY OUT AND SINCE THE TRAIN IS TRAVELING AT 1 MILE A MINUTE, IT WILL TAKE 2 MINUTES TO PASS THROUGH THE TUNNEL