Question

You have a 1M KCl solution and need to make 50ml of 0.1 KCl. How would you make it?

Answer 1

Supposing the missing unit on "0.1 KCl" to be "M":
(50 mL) x (0.1 M) / (1 M) = 5.0 mL
So take 5.0 mL of the 1 M solution and dilute it with solvent (presumably water, but the question didn't actually say that) until the final volume is exactly 50 mL.