# aqa biology aslevel calculation question FVC

At 1 second:
B is 0.8, A is 4.2.
Want to calculate % decrease from Group A
So: (group B)/group A x 100
0.8/4.2 * 100 = 19%

You have been doing (4.2-0.8)/4.2 x 100. The question asks % decrease compared with group A.
(edited 1 month ago)
Original post by BankaiGintoki
At 1 second:
B is 0.8, A is 4.2.
Want to calculate % decrease from Group B
So: (group A)/group B x 100
0.8/4.2 * 100 = 19%
You have been doing (4.2-0.8)/4.2 x 100. The question asks % decrease from B, so do group A/ group B
thank you for explaining i get it, but i thought for % q's we always do ((old-new)/ old value) x 100? it has worked for other qs so im just confused how it doesn't work for this one
Original post by ricecakes1
thank you for explaining i get it, but i thought for % q's we always do ((old-new)/ old value) x 100? it has worked for other qs so im just confused how it doesn't work for this one

Here you are comparing the value in 2 different groups, groups A and group B, from group A. The 80% value is the % change between the 2 different groups from group A.
(edited 1 month ago)