How much 1 : 25 solution and 1 : 500 solution should you mix to make 1 L of a 1 : 250 soaking solution? Answers are rounded to the nearest whole number.

Step 1. Convert ratios to percentages. 1 : 25 = (1/25) x 100 = 4% 1 : 500 = (1/500) x 100 = 0.2% 1 : 250 = (1/250) x 100 = 0.4% Step 2. Set up alligation. Higher: 4% Lower: 0.2% Target: 0.4% Step 3. Calculate parts. Parts of 4% = 0.4 - 0.2 = 0.2 parts Parts of 0.2% = 4 - 0.4 = 3.6 parts Total parts = 0.2 + 3.6 = 3.8 parts Step 4. Calculate volumes for 1000 mL (1 L). Vol of 1 : 25 (4%) = (0.2 / 3.8) x 1000 = 52.63 mL (rounds to 53 mL) Vol of 1 : 500 (0.2%) = (3.6 / 3.8) x 1000 = 947.37 mL (rounds to 947 mL)