Well, the answer quite simple ....there are 4! ways to arrange these numbers...and as 4! = 4*3*2*1 = 24
hence 24 is the correct answer....
u can also remember it by theorem of multiplication as.....in first place (I.e. first code can be any no. out of 4,5,2&7 ....so 4*.....
as first place is acquired by a certain no. that leaves three no. to fill third place and when third place I'd occupied it leaves 2 numbers to fill second place and lastly only one no. to fill the last place .....so it's result will be like 4*3*2*1.
I know this is pretty much confusing ....but still I tried my best....
if anything troubles u here feel free to ask me
Not sure is this is right but if the chemist wants to make the solution 35% acidic then he can use all of the 30% acid and 5% of the 45% acid.
The absolute value of rational number 3.7 is 3.7
I think it's the Multiplication Property of Equality.
Hope this helps you! :)