A radio sells for £63, after a 40% increase in the cost price. Find the cost price.

X+2/5X = 63 or 63 = 140%

First we need to understand that the original price (X) has been increased by 40%. Hence, by 2/5 (40/100 = 40%) of its original value, in other words, 2/5X.

To find the answer we the have to add the original value (X) to the amount of which it has increased (2/5X) and equate that to the end value that it's been given to us (£63). By solving this equation we'll be able to find the asnwer we are looking for. (£45)

OR

X = 100%, the value it has been increased by is 40% so: 63 = 140%X

X = £45