Question

Mike is three times as old as his little sister, Mary. In 4 years, he will be twice as old as Mary. How old is Mike?

Answer 1

Mary = x
Mike = 3x
In 4 years Mike will be twice as old as mary =2(x+4)

Answer 2

can u continue from there?

Answer 3

No... I don't get it

Answer 4

Did u follow the way i set up the variables?

Answer 5

Solve a system with two equations one being x=3y and the second being y+4=2x. X-mike Y- mary

Answer 6

i guess u can solve it like that too using subsitution

Answer 7

I solved it differently but how were u taught to solve it in skewl?

Answer 8

I soved it like this
3x+4 = 2(x+4)
So basically i set up the equation descrobong mikes age in 4 yrs in two different ways and then i solved for x

Answer 9

Mike is three times as old as his little sister, Mary. In 4 years, he will be twice as old as Mary. How old is Mike?
Let Mike's age be "3x" yrs.
Mary's age is "x" yrs.

Mike's age will be "3x+4" yrs.
Mary's age will be "x+4" yrs.

Mike = 2(Mary)
3x+4 = 2(x+4)
3x+4 = 2x + 16

x = 4 yrs. (Mary's age NOW)
3x = 12 yrs. (Mike's age NOW)
Mike is 12 years old.