Question 702005: Bill Phipps is 6 times as old as his 5-year old niece. How long will it be before he is twice as old as she?
Thanks for your help :)
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! Bill Phipps is 6 times as old as his 5-year old niece
So Bill is 6*5 = 30 years old
In x years, he will be 30+x years old
In x years, she will be 5+x years old
If you want to know when he will be twice her age, simply say
30+x = 2(5+x)
Then solve for x
30+x=2(5+x)
30+x=10+2x
x=10+2x-30
x-2x=10-30
-x=10-30
-x=-20
x=(-20)/(-1)
x=20
So it will take 20 years for him to be twice as old as her.
Notice how adding 20 years to 30 makes him now 50. Adding the same 20 years to 5 makes her now 25. Finally, notice that 50 is double of 25. So the answer checks.
|
|
|
