Answer:
21
Step-by-step explanation:
you multiply 30 by 0.7 and you get 21.
Answer: 21
Step-by-step explanation: 30=100%
3=10%
0.3=1%
3*7=21
21=70%
9
H=1/2 * B
N=H-5= 1/2 * B-5
B+H+N= B+(1/2 *B) + (1/2 *B-5)=31
2B-5=31
B=18
H=1/2 *B=9