Answer:
B). n = 1.40
Explanation:
0.7n + 0.8n = 2.1
(0.7n + 0.8n) = 2.1
1.5n = 2.1
/1.5 /1.5
n = 1.40
hope this helped!
0.7n+0.8n=2.1
1.5n=2.1
n=1.4
Therefore, the answer is B.
3.5m questions
4.5m answers