If my age was thrice my sister’s 3 years ago and will be twice her age next year. What is my age?

My present age of my sister= x
assumed.

3 years before her age =
x-3.

My  age 3 ters ago =  3tines my sister's age=
3(x-3).

Next year my sister'age =
x+1.

My age next year = 3(x-3) + 4 this twice sister's age
next year = 2(x+1).

So the required equation
is:

3(x-3)+4 = 2(x+1). We solve
this.

3x-9 +4= 2x+2

3x-2x =
2+9-4

x = 7.

So my sister' age
= 7.

My age = my age next year -1 = 3(x-3)+4 -1 = 3x-9+3 =
3x-6 = 7*3-6 = 15

My age = 15 and my sister's age =
7.