math_fanatic
|
1) To answer the first question, I need to know something about how resistance is measured. I looked it up on wikipedia and it looks like you can put resistors in a series and then test the total resistance of a group of resistors. I'm going to go on that assumption since it seems the most likely scenario to solve this type of problem.
First: Divide the boxes into two groups. Take a resistor from each box in group 1 and put them in a series. If the resistance is 520 (the sum of the resistances of all of the resistors in the series), you know the 120 ohm box is in that group. If the total resistance is 500, the 120's are in the other group of 5 boxes.
Second: After you've decided which group of 5 boxes your 120 ohm resistors are in, take a resistor from each box then put one aside. Place the remaining 4 in 2 series of 2 each. Test the single resistor first. If it's 120, you're done in 2 measurements. If not, the 120's are in one of the series of 2 and you must take 2 additional measurements.
Third: Test one of the series of two resistors. If you get 220, the 120's are in that group of two. If you get 200, they're in the other group of two.
Fourth: After you identify the series of 2 that your 120's are in, test 1 of the resistors in that series. If the resistance is 120, that one belongs to the box of 120's. If not, the one you didn't measure is from the box of 120's.
This solution requires either 2 or 4 measurements. If there is something I'm missing about measuring resistance, please explain. I'm not a physicist or an electrical engineer.
2) I don't know what you mean by a "family". Do you mean these are the only people in the family (which is not very likely) or do you just mean that these are people that are in a family with many people not listed here? I'm going to try to answer both questions, starting with the latter.
SOLUTION 1:
A female can be a grandmother, a mother, a child, a grandchild, a sister, a daughter, a mother-in-law, and a daughter -in-law.
A male can be a grandfather, a father, a child, a grandchild, a brother, a son, and a father - in -law.
For the females this leaves a mother, 2 children, 1 grandchild, 1 sister, and 1 daughter.
A female can be a mother, a child, a grandchild, a sister, and a daughter.
For the males this leaves a father, 1 child, and a son. A male can be all of these things.
So the minimum number of people in an extended family with these titles is 4.
SOLUTION 2:
Under the condition that these are the ONLY people in the family and they must all be related to each other by the titles you've listed, the answer is 7. Here is the breakdown.
GM = GRANDMOTHER, GF = GRANDFATHER, F1 = FATHER 1, F2 = FATHER 2
M1 = MOTHER 1, M2 = MOTHER 2, C1 = CHILD 1, C2 = CHILD 2, C3 = CHILD 3, C4 = CHILD 4
G1 = GRANDCHILD 1, G2 = GRANDCHILD 2, G3 = GRANDCHILD 3, B = BROTHER
SS1 = SISTER 1, SS2 = SISTER 2, S1 = SON 1, S2 = SON 2, D1 = DAUGHTER 1, D2 = DAUGHTER 2
FIL = FATHER IN LAW, MIL = MOTHER IN LAW, DIL = DAUGHTER IN LAW
Person 1 is: GM, M1, MIL
Person 2 is: GF, F1, FIL
Person 3 is: F2, C1, S1
Person 4 is: M2, DIL
Person 5 is: C2, G1, SS1, D1
Person 6 is: C3, G2, SS2, D2
Person 7 is: C4, G3, B, S2
Family tree:
P1(Person 1) is the grandmother of P5, P6, P7. P1 is the mother of P3, and mother in law of P4.
P2 is the grandfather of P5, P6, P7. P2 is the father of P3, and father in law of P4.
P3 is the father of P5, P6, P7. P3 is the child and son of P1 and P2.
P4 is the mother of P5, P6, P7. P4 is the daughter in law of P1 and P2.
P5 is the child and daughter of P3 and P4. P5 is the grandchild of P1 and P2. P5 is the sister of P6,P7.
P6 is the child and daughter of P3 and P4. P6 is the grandchild of P1 and P2. P6 is the sister of P5,P7.
P7 is the child and son of P3 and P4. P7 is the grandchild of P1 and P2. P7 is the brother of P5,P6.
 Posted 159 day ago
|
