All CD Heaven stores were given the same number of a popular CD to
sell for £24. In their two week sale each store reduces the
price of the CD by 25% ... How many CDs did the store sell at each
There are two sets of numbers. The second is the result of the
first after an increase by a constant percentage. How can you find
that percentage if one set of numbers is in code?
If a sum invested gains 10% each year how long before it has
doubled its value?
The area of the original rectangle was wb.
The area of the altered rectangle is pw x 1.1b.
Since the two areas are equal,
1.1 pwb = wb
1.1 p = 1
so p = 1/1.1 = 10/11
So the width is 10/11 of its original value, so it has been decreased by 1/11, which as a percentage is 9 and 1/11 %, or 9.09 % to 2.d.p.