SSC Test Questions
Three years ago the average age of A and B was 18 years. If C joins them today, the average becomes 22 years. How old is C now?
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Average of A and B = 18 years
So, (A+B)÷2 = 18
Now after three years and adding C,
(A+B+C)÷3 +3 = 22, Equation-{1}
So, (A+B+C+9)÷3 = 22
A+B+C+9 = 66
A+B+C = 57
A+B = 57-C
So, Putting value of A+B in Equation 1,
(57-C)÷2 = 18
57-C = 36
So, C = 57-36 = 21
So, C will be 21 years old.
So, (A+B)÷2 = 18
Now after three years and adding C,
(A+B+C)÷3 +3 = 22, Equation-{1}
So, (A+B+C+9)÷3 = 22
A+B+C+9 = 66
A+B+C = 57
A+B = 57-C
So, Putting value of A+B in Equation 1,
(57-C)÷2 = 18
57-C = 36
So, C = 57-36 = 21
So, C will be 21 years old.
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