The value of 2 is 3.5
We need to find the value of 3, 4, 5
Let us use the ratio method
2 : 3.50
3 : x
Use the cross multiplication
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2x = 10.5
Divide both sides by 2
x = 5.25
The cost of 3 = 5.25
Do the same with 4
2 : 3.50
4 : x
Use the cross multiplication

2x = 14
Divide both sides by 2
x = 7
The cost of 4 = 7
Do the same with 5
2 : 3.50
5 : x
Use the cross multiplication

2x = 17.5
Divide both sides by 2
x = 8.75
The cost of 5 = 8.75