what's in a age?...

Algebra Level 1

The older brother Bob is two year older than his little sister Alice. Taken together, the sum of their ages is 8. help bob to find his age

6 not enough information (it's just a dummy answer) 3 5

9 solutions

Joji Thomas
Mar 1, 2014

let x be Bob's age and y be Alice's age. Then, x+y=8 + x-y=2 ==>2x=10==>x=10/2=5

Use , common sense, no need of equations.

Sahba Hasan - 7 years, 2 months ago

Everybody is not so clever as you

Swapnil Diganta - 7 years, 2 months ago

What common sense are u talking about ?

Kushagra Sahni - 7 years, 2 months ago

8 -2 = 6... :)

Faaiq Awang - 7 years, 2 months ago

kindly read the problem first.....=D

suyash singh - 7 years, 2 months ago

I thought you wanted Alice's age. My mistake, read the question wrong!

Muhammad Amir - 7 years, 2 months ago

Niteesh Kanneganti
Mar 27, 2014

olet age of alice be 'x' so bob's age is "2+x" given 'x+x+2=8' hence x=3..so bob's age is 5

Prajwal Kavad
Apr 9, 2014

let age of alice be 'x' so bob's age is "2+x" given 'x+x+2=8' hence x=3..so bob's age is 5

Yasmine Babers
Apr 5, 2014

x+x+2=8 then 2x+2=8 then 2x=6 then x=3 since bob =x+2 Then=3+2=5

Swapnil Diganta
Apr 5, 2014

ধরি Alice এর বয়স X বছর।তাই Bob এর বয়স X+2 বছর ।বয়সের যোগফল 2X+2=8 এর সমাধান করলে ANSWER হবে 3 যা এলিসের বয়স এবং এর সাথে 2 যোগ করলে উত্তর হবে 5 ।

Mohd Naim Mohd Amin
Mar 26, 2014

Hello,

Let x = Bob's age, y = Alice's age,

x = y + 2(1st equation), substitute 1st equation into 2nd equation,

x + y = 8(2nd equation),

y + y + 2 = 8

2y=6

y=3 , x= 2 + 3 =5, therefore, Bob's age is 5 years old...

thanks...

Angelena Coralie
Mar 22, 2014

x+2 is age of BOB and x is age of her sister. so (x+2)+x=8 / x+2+x=8/ 2x=8-2/ 2x=6/ x=3/ 3 is age of her sister and 3+2= 5/ 5 is age of Bob

Ahmad Hunjra
Mar 19, 2014

let x be Bob's age and y be Alice's age. Then, x+y=8 + x-y=2 ==>2x=10==>x=10/2=5

Krishna Garg
Mar 17, 2014

Let X & Y be tha age of Bob and his sister. So, X + Y =8 and X - Y = 2

by subtracting these two equations 2 X = 106 That is X =5 and Y = 3 So Bob's age is 5 Ans

K.K.GARG,India