Ok, so lets call James "J", and Alex "A" for short. Since James is 3 years younger, when we subtract James's age from Alex, the answer has to be 3: A - J = 3 We also know that if we add their ages together 12 years from now, when they are each 12 years older, the answer has to be 53: A+12 + J+12 = 53 Then we can subtract 24 (because 12+12=24) from both sides of the equation: A + J = 29 Now we have two equations, and two variables, which is exactly what we want. Let's go back to the first equation and solve for A: A - J =3 A = 3 + J Since we know what A is equal to (3+J) we can put that into our second equation. So where you see "A" in the second equation, put 3+J: A + J = 29 3+J + J = 29 Now solve for J: 3+J + J = 29 3 + 2J = 29 2J = 26 J = 13 Now we know what J equals, or how old he is. Just like before, we can now put this number into our first equation: A - J = 3 A - 13 = 3 A = 16 So Alex is 16 years old, and James is 13.
Comments
Let x be no. of years from now.
x years from now, sharon = 48 + x years old
x years from now, sam = 3 + x years old
4 years from now,
48 + x = 4 (3 + x)
48 + x = 12 + 4x
4x - x = 48 - 12
3x = 36
x = 12
Where x= number of years
Sharon's age + number of years = 4(Sam's age + number of years)
48 + x = 4(3 + x)
multiply thru
48 + x = 12 + 4x
Get the x's on the same side of the equation
36 = 3x
Solve for x
x = 12
So, in 12 years Sharon will be 4 times as old as Sam. To check, add 48 + 12 = 60, and add 3 + 12 = 15. 60/4 = 15.
Let x = no. of years for Sharon to be 4 times as old as Sam.
48 + x = 4(3 + x)
48 + x = 12 + 4x
48 - 12 = 4x - x
36 = 3x
x = 36 / 3
x = 12
Answer: 12 years must pass for Sharon's age to be 4 times the age of Sam.
Proof:
48 + 12 = 4(3 + 12)
60 = 12 + 48
60 = 60
Ok, so lets call James "J", and Alex "A" for short. Since James is 3 years younger, when we subtract James's age from Alex, the answer has to be 3: A - J = 3 We also know that if we add their ages together 12 years from now, when they are each 12 years older, the answer has to be 53: A+12 + J+12 = 53 Then we can subtract 24 (because 12+12=24) from both sides of the equation: A + J = 29 Now we have two equations, and two variables, which is exactly what we want. Let's go back to the first equation and solve for A: A - J =3 A = 3 + J Since we know what A is equal to (3+J) we can put that into our second equation. So where you see "A" in the second equation, put 3+J: A + J = 29 3+J + J = 29 Now solve for J: 3+J + J = 29 3 + 2J = 29 2J = 26 J = 13 Now we know what J equals, or how old he is. Just like before, we can now put this number into our first equation: A - J = 3 A - 13 = 3 A = 16 So Alex is 16 years old, and James is 13.
Let's say x is the number of years. Thus:48+x=4(3+x). So: 48+x=12+4x. Then 36=3x. So: x =12 Checking 48+12=4(3+12) 60=4*15. There's your answer.
In 12 years, Sharon will be 60, four times 15 which will be Sam's age.
,let x=years
48 +x= sharon's age in x years
3+x=sam's age in x years
48+x=4(3+x)
48+x=12+4x
36=3x
x=12 years
let it be x yrs.
then
48+x=4(3+x);
48+x=12+4x;
48-12=4x-x;
36=3x;
x=12;
thus after 12 yrs sharon will be 60 & sam 15yrs. 60=4*15;
hence after 12yrs sharon will be 4 times sam's age
12
Sharon + X number of years = 4* (Sam +X number of years)