Seven years ago, Varun's age was five times
the square of swati's age. Three years hence
Swati's age will be two fifth of Varun's age.
Find their present ages.
Answers
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Let the age of swati be x
Let the age of varun be y
Seven years ago , swati's age = x - 7
Varun's age = y - 7
y - 7 = 5(x - 7)2
y - 7 = 5[x2 - 14x + 49 ]
y - 7 = 5x2 - 70x + 245
y = 5x2 - 70x + 252
After three years
Swati's age , x + 3
Varun's age , y + 3
x + 3 = 2/5[y + 3]
5x + 15 = 2y + 6
5x + 15 = 2(5x2 - 70x + 252) + 6
5x + 15 = 10x2 - 140x + 504 + 6
5x + 15 = 10x2 - 140x + 510
10x2 - 145x + 495 = 0
2x2 - 29x + 99 = 0
2x2 - 18x - 11x + 99 = 0
2x(x - 9) - 11(x - 9) = 0
(2x - 11)(x - 9) = 0
x = 11 / 2 , x = 9
By taking x = 9 , y = 27
Ans: Swati's age = 9 , Varun's Age = 27
Cheers!
Best of Luck!
Let swati age be x
Varun y
AtQ
X-7=(Y-7)^2 EQ 1
(x+3)=2/5(y+3) eq2
From eq 1 and 2 we get
Varun age= 27 and swati =9 years