That great good for you I hope this helps
Answer:
3 times
Explanation:
When the dough is folded, it increases by a constant factor. We can model the growth of the thickness using the exponential growth model

Where:
Initial thickness,
= 2mm
Growth factor, r =8%=0.08
We want to find the smallest number of times Soon Yi will have to roll and fold the dough so that the resulting dough is at least 2.5mm.
i.e When 

Therefore, the smallest number of times Soon Yi will have to roll and fold the dough so that the resulting dough is at least 2.5mm thick is 3.
Answer:
Amount to spend = $18.50
Purchased banana =$1.50
Apple Juice =$1.55
Gasoline $2.35
$1.50 + $1.55 = $3.05
18.50 - 3.05 = 15.45
1 Gallon of Gasoline = 2.35
Therefore,
2.35 x 6 = 14.1
15.35 - 14.1 = 1.25
To avoid exceeding budget, he can only buy
6 gallons of gasoline