1. A cupcake show makes and delivers specialized cupcakes. It will cost someone $30 for 10 cupcakes and $67.50 for 25 cupcakes. This total includes the cost per cupcake and
delivery fee. How much does each cupcake cost? (enter your answer with just the number,
no $ sign)

2.5

Explanation:

The given costs for the purchase and delivery of the cupcakes are;

The cost of 10 cupcakes and the delivery fee = $30

The cost of 25 cupcakes and the delivery fee = $67.50

Let 'c' represent the fixed cost of delivery of the cup cakes, and let 'x' represent the cost of each cup cake, we have;

30 = 10·x + c...(1)

67.50 = 25·x + c...(2)

Subtracting equation (1) from equation (2) gives;

67.50 - 30 = 37.50 = 25·x - 10·x + c - c = 15·x

∴ x = 37.50/15 = 2.5

The cost of each cupcake, x = 2.5

(∴ The delivery fee = 30 - 10 × 2.5 = 5)

The cost of each cupcake is 2.5.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

it is b that is the answer.