If you were to dilute a sample 15 followed by a second dilut

If you were to dilute a sample 1:5 followed by a second dilution of 1:10, what is the final dilution of the original sample?

Solution

let us consider 1:5 as 1/5 and 1:10 as 1/10

then 1/5 * 1/10 =1/50

1/50 = 1:50

Thus the original solution is fifty times more concentrated then the final dilution