Ihave 2 problems
a machine in a factory has a failure rate of 2.5%. i the machine makes 15,200 items per day, how many are defective?
and
the cost of ben`s energy bill increases by 63% in the three months of winter compared to the three months of summer, ben`s energy bill is £205
what is ben`s bill for the three winter months?

First problem:

Multiply 15,200 x 2.5

Second problem
$205 would be the energy bill for the first month.
205 x . 63  = 
Take this total then add it to the 205.00 this will give you the cost of the second month.

Then take the cost of the second month and multiply it by 0.63. Add this, which represents the increase, to the amount of the second month. This will give you the cost of the third month.

Add all these together and you get the cost of the three months.