Liquid A and liquid B are mixed to make liquid C - Edexcel - GCSE Maths - Question 14 - 2020 - Paper 1

To find the mass of liquid B, we can use the formula:

$\text{Mass} = \text{Density} \times \text{Volume}$

Substituting the known values:

$\text{Mass of B} = 280\text{kg/m}^3 \times 30\text{m}^3 = 8400\text{kg}$

Now, we can calculate the total mass and total volume to find the density of liquid C:

1. Total Mass: $\text{Total Mass} = \text{Mass of A} + \text{Mass of B} = 1400\text{kg} + 8400\text{kg} = 9800\text{kg}$

2. Total Volume: $\text{Total Volume} = \text{Volume of A} + \text{Volume of B} = 20\text{m}^3 + 30\text{m}^3 = 50\text{m}^3$

3. Density of Liquid C: $\text{Density of C} = \frac{\text{Total Mass}}{\text{Total Volume}} = \frac{9800\text{kg}}{50\text{m}^3} = 196\text{kg/m}^3$