Question

Freddy is 4 years older than 8 5times his grandsons age. The sum of their ages is greater than 67. What is the youngest age Freddy’s grandson can be?

Answer 1

Answer: 8 years

Step-by-step explanation:

Let's have x represent the grandson's age and y represent Freddy's age.

First, start by forming your equations,

y=8x+4 and x+y=67

Then substitute y=8x+4 into the second equation which gives you

x+(8x+4)=67

Then solve for x,

9x+4=67

9x=63

x=7

You can then put x into the first equation to find y,

y=8(7)+4

y=60

Then you substitute into the second equation to get,

7+60=67

Since the answer needs to be greater than 67, the grandson's minimum age would have to be 8.

So x=8

Answer 2

Answer: The age of Freddy's grandson is 7 years.

Step-by-step explanation:

We have given that,

Let the present age of grandson be x

Let the present age of Freddy's age be 8.5x+4

(∵ Freddy is 4 years older than 8.5 times of his grandson)

According to question,

8.5x+4+x >67 (∵ we have given that sum is greater than 67)

⇒ 9.5x+4 >67

⇒ 9.5x > 67-4

⇒ 9.5x > 63

⇒ x >
`(63)/(9.5)`

⇒ x >
`(630)/(95)`

⇒ x > 6.6

As we know that age can't be in decimals so we use the nearest integer i.e. 7

So ,

The youngest age of Freddy's grandson age will be 7 years.