1. First you have to find a number evenly divisible by 3. That leaves 30 and 45. Five years ago the father was either 25 or 40. What do you think the answer is?
2. Which choices are evenly divisible by 4? Which answer do you think is right?
1. A father is three times as old as his son. Five years ago the sum of their ages was 30. How old is the father now? Choices; 30, 35, 40, 45, 50
2. A mother is four times as old as her daughter. In two years, the sum of their ages will be 44. How old is the mother now? Choices: 30, 32, 34, 36, 38
3 answers
1.
Let the son's present age be x
then the father's present age is 3x
Five years ago :
son's age = x-5
father's age = 3x-5
so
x-5 + 3x-5 = 30
4x = 40
x = 10
So the son is now 10 and the father is now 30
Now you do #2 the same way.
Let the son's present age be x
then the father's present age is 3x
Five years ago :
son's age = x-5
father's age = 3x-5
so
x-5 + 3x-5 = 30
4x = 40
x = 10
So the son is now 10 and the father is now 30
Now you do #2 the same way.
mum is 34
2 answers