Answer:
D
Step-by-step explanation:
i had the same answer and got it right
Alright
so
28% of 2 m³=0.28 times 2=0.56 m³ of silt in the first mixture
13% of the 1 m³=0.13 times 1=0.13 m³ of silt in 2nd
total is 0.56 m³+0.13 m³=0.69 m³ of silt
and the total is 2m³+1m³=3m³
so
0.69/3=0.23=23%
answer is D