TITLE: A is x% more than B
QUESTION [5 upvotes]: I am taking the AMC10 test, and I don’t want to lose points on silly misunderstandings. When a question says “A is x% greater/less than B”, or things like that sometimes with money, which respect should we take if it doesn’t tell me which? And please write a formula to make it clear. Thanks!

REPLY [2 votes]: Whenever you are given that a quantity $A$ is $x\%$ greater or less than $B$ the first thing is that the comparision is done with respect to the quantity $B$.
Look it in another way. So how do you calculate the $\%$ increase or decrease in a quantity with respect to another quantity.
If it is said that the quantity $A$ is $x\%$ greater  than quantity $B$ what you mean is : $$\frac{A-B}{B}=\frac{x}{100}$$
And if the quantity is $x\%$ less than $B$ then :
$$\frac{B-A}{B}=\frac{x}{100}$$
Hope this helps ...