Question

Six toilet rolls cost $1.99. Nine toilet rolls cost $2.69. Is cost directly proportional to number of toilet rolls? Explain your reason!​

Answer 1

No because to buy nine rolls would be $2.69 but to buy six and then three to make nine then it would be $2.985 which is more expensive.

Explanation:

$1.99 divided by 2 = 0.995

$1.99 + 0.995 = $2.985

$2.985 > $2.69

Hope this helps!!! :)

Answer 2

not directly proportional

Explanation:

if the cost is directly proportional to number of rolls , then the unit cost for both will be equal.

first

one roll costs $1.99 ÷ 6 = $0.33 ( to 2 decimal places )

second

one roll costs $2.69 ÷ 9 = $0.30 ( to 2 decimal places )

since the unit costs are different there is not a directly proportional relationship.