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Amita is 2 years elder than her friend Amrita. Amita's father is twice as old as Amita, and Amrita is twice as old as her sister. The ages of Amita's father and Amrita's sister differ by 43 years. The difference between the ages of Amita and Amrita is:
2
4
1
3
2
Express all ages in terms of Amrita's age (A), substitute into the father-sister age difference equation to find A, and then calculate the difference between Amita and Amrita.
Amita is 2 years elder than Amrita. Amita's father is twice as old as Amita. Amrita is twice as old as her sister. The ages of Amita's father and Amrita's sister differ by 43 years.
FтИТS=43
Express all ages in terms of Amrita's age (A), substitute into the father-sister age difference equation to find A, and then calculate the difference between Amita and Amrita.
Confusing Amita and Amrita's names, or setting up the age difference between the wrong family members.
Step 1: Define variables for each person's age
Let Amrita's age be x. Since Amita is 2 years elder than Amrita, Amita's age is x+2. Amrita is twice as old as her sister, so her sister's age is 2xтАЛ. Amita's father is twice as old as Amita, so the father's age is 2(x+2).
Amrita=x,Amita=x+2,Sister=2xтАЛ,Father=2(x+2)
Step 2: Formulate the equation using the given age difference
We are given that the ages of Amita's father and Amrita's sister differ by 43 years. Setting up this equation gives: 2(x+2)тИТ2xтАЛ=43
2(x+2)тИТ2xтАЛ=43
Step 3: Solve the equation for x
Expanding and simplifying the equation: 2x+4тИТ0.5x=43тЯ╣1.5x=39тЯ╣x=26 Thus, Amrita's age is 26 years.
x=26
Step 4: Find the difference between Amita's and Amrita's ages
Amrita's age is x=26 years. Amita's age is x+2=28 years. The difference between Amita and Amrita is 28тИТ26=2 years.
Difference=28тИТ26=2┬аyears
A is correct because the calculated age difference between Amita and Amrita is 2 years.
Age word problems can always be systematically solved by defining all ages in terms of a single variable and translating the verbal statements into an algebraic equation.