The difference between the tom and harry is 6 years. 10years later the product of their ages will be 280. How old are tom and harry now?
Answers
ɢɪᴠᴇɴ :-
The difference between the tom and harry is 6 years. 10years later the product of their ages will be 280.
ᴛᴏ ғɪɴᴅ :-
- Tom's age
- Harry's age
Sᴏʟᴜᴛɪᴏɴ :-
➦ Let Tom's age be x years
And,
➦ Harry's age be y years
Then,
➭ ( x - y) = 6
➭ x = (6 + y). --(1)
10 years later,
Tom's age = (x + 10) years
Harry's age = (y + 10) years
Product = xy = 280
➮ (x + 10)(y + 10) = 280.
➮ ( 6 + y + 10)(y + 10) = 280 --(from -1)
➮ (y + 16)(y + 10) = 280
➮ y² + 10y + 16y + 160 = 280
➮ 26y + y² = 280 - 160
➮ y² + 26y - 120 = 0
➮ y² + 30y - 4y - 120 = 0
➮ y( y + 30) - 4( y +30) = 0
➮ ( y - 4) ( y + 30) = 0
➮ y = 4. or y = -30
Hence,
➦ Age can't be negative.
So,
We take y = 4
Put y = 4 in (1) , we get,
➮ x = 6 + y
➮ x = 6 + 4
➮ x = 10
Hence,
Age of :-
✑ Tom = x = 10 years
✑ Harry = y = 4 years
ꜱᴏʟᴜᴛɪᴏɴ :
- Let's Tom's age be x
- Let's Harry's age be y
ACQ :-
➨ x - y = 6
➨ x = y + 6 ------- ( 1 )
10 years later
➨ ( x + 10 ) * ( y + 10 ) = 280
➨ xy + 10x + 10y + 100 = 280
Substitute value of x from ( 1 )
➨ y ( y + 6 ) + 10 ( y + 6 ) + 10y = 280 - 100
➨ y² + 6y + 10y + 60 + 10y = 180
➨ y² + 26y = 180 - 60
➨ y² + 26y = 120
➨ y² + 26y - 120 = 0
By splitting middle term
➨ y² + 30 - 4y - 120 = 0
➨ y ( y + 30 ) - 4 ( y + 30 ) = 0
➨ ( y - 4 ) ( y + 30 ) = 0
y - 4 = 0 y + 30 = 0
y = 4 y = - 30
Age can't be -ve so 4 is right
Age can't be -ve so 4 is right Put value of y in ( 1 ) to find value of x
➨ x = y + 6
➨ x = 4 + 6
x = 10
Tom's age is 10 years and Harry's age is 4 years