Suppose Julio started with a drawing pad and a pencil.
$1.80 + $1.20 = $3.00 < $1.86 + $1.23 < $2.00 + $1.50 = $3.50
Double these supplies will cost between 2 × $3.00 and 2 × $3.50.
Suppose Kira started with 2 pencils.
2 x $1.23 = $2.46
Think about more items Kira could buy so that her total cost is more than $4 but less than $6.
Suppose Ida started with 1 drawing pad and 2 pencils.
$1.80 + ($1.10 x 2) = $4.00 < $1.86 + ($1.23 x 2) < $2.00 + ($1.25 x 2) = $4.50
Think about more items Ida could buy so that her total cost is more than $8 but less than $9.
Answer
Julio: $6 - $7
one paintbrush
two drawing pads
Kira: $4 - $6
two pencils
one drawing pad
Ida: $8 - $9
two pencils
three drawing pads