Question

Lee is y years old. toby is 8 years younger than lee.

the sum of their ages is less than 41
1)write down in terms of y an inequality to show this information.
2) work out the oldest age that lee can be. give your answer as a whole number of years

Answer 1

1) 2y-8<41

2) 24

Explanation:

1) 8 years younger would be -8.

So you do y + (y-8)

2) 2y-8<41

2y<49

y<24.5

The highest integer (whole number) below 24.5 is 24.

Answer 2

y + (y-8) < 41

lee <24 in whole numbers

Explanation:

lee =y

toby = lee -8

= y-8

sum of their ages < 41

lee + toby < 41

y + (y-8) < 41

combine like terms

2y-8 <41

add 8 to each side

2y < 49

divide by 2

y < 49/2

y < 24.5

y <24 in whole numbers