Answer:
Andy is 7 and Andy's father is 32
Step-by-step explanation:
I used the guess and check method, starting from Andy being 5.
If Andy was 5, his dad would be 30, and his sister would be 10. 5+30+10=45
Too low
If Andy was 6, his dad would be 31, and his sister would be 12. 6+31+12= 49
Too low again
If Andy was 7, his dad would be 32, and his sister would be 14. 7+32+14=53
Andy is 7 and his Father is 32
Another method you could use is to make an equation and solve.
A = Andy
S= Sister
F= Father
S=2A (Andy's sister is twice the age of Andy)
F=A+25 (Andy's father is 25 years older then Andy)
A+S+F=53 (The total of their ages is 53 years)
Substitute your variables
A+(2A)+(A+25)=53
Subtract 25 from both sides
A+(2A)+(A+25)=53
-25 -25
A+(2A)+(A)=28
Add up your variables
A+(2A)+(A)=28
4A=28
Divide to find A
4A=28
A=7
Now solve for the Fathers age
F=A+25
F=32
Andy is 7 and his Father is 32
