H _ S
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6 .
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X ,
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Y ,
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Z .
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Z = 3 Y ,
Z = X 2 ,
Y = 2 X .
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6 X = X 2
_ N D
X = 6 Clue
HIS YOUNGER BROTHER WAS 6. LET HIS AGE BE X, DIMPLE'S AGE BE Y, AND HIS FATHER'S AGE BE Z. THEN Z=3Y, Z=X2, Y=2X. SO 6X=X2 AND X=6 HE IS 16 YEARS OLD. WHEN I WAS 4 YEARS OLD, MY BROTHER WAS 2 YEARS OLD (HALF MY AGE), SO MY BROTHER IS 2 YEARS YOUNGER THAN ME. WHEN I AM 18 YEARS OLD, MY BROTHER WILL BE 16 YEARS OLD AS HE IS 2 YEARS YOUNGER THAN ME THREE SISTERS AND TWO BROTHERS. THIS CAN BE SOLVED BY SIMPLE DEDUCTION, BUT IF ALGEBRA IS USED LET X BE THE NUMBER OF SISTERS AND Y THE NUMBER OF BROTHERS: X+ 1= 2Y Y+ 1= X THEREFORE, Y + 1+ 1= 2Y SO Y =2 OR X + 1= 2X - 2 SO X = 3 ONCE, BECAUSE AFTER YOU SUBTRACT IT'S NOT 25 ANYMORE