SOLUTION: sir please help me solve my question john is 10 years older than marcus,3times johns age 5years from now will be the same as 5times marcus age 5years ago.how old is jo

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Question 950655: sir please help me solve my question john is 10 years older than marcus,3times johns age 5years from now will be the same as 5times marcus age 5years ago.how old is john now. Thank u
Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
let m = marcus age today.
let j = john age today.

john is 10 years older than marcus.

equation for this is j = m + 10

3 times johns age 5 years from now will be the same as 5 times marcus' age 5 years ago.

equation for this is 3 * (j + 5) = 5 * (m + 5)

you have 2 equations that need to be solved simultaneously.

they are:

j = m + 10
3 * (j + 5) = 5 * (m + 5)

replace j in the second equation with (m + 10) that it is equal to from the first equation.

you get:

3 * ((m + 10) + 5) = 5 * (m + 5)

simplify to get:

3 * (m + 15) = 5 * (m + 5)

simplify further by performing the multiplication to get:

3 * m + 45 = 5 * m + 25

subtract 25 from both sides of the equation and subtract 3 * m from both sides of the equation to get:

45 - 25 = (5 * m) - (3 * m)

simplify to get:

20 = 2 * m

solve for m to get:

m = 10

if m = 10, then j = m + 10 becomes j = 20

you have:

m = 10
j = 20

how old is john now?

john is 20 years old today.
he is 10 years older than marcus who is 10 years old today.

5 years from now john will be 25 and marcus will be 15.

3 times john's age 5 years from now is equal to 3 * 25 which is equal to 75.

5 time marcus' age 5 years from now is equal to 5 * 15 which is equal to 75.

original problems statements are true, so the solution must be good.