Answer:
14 hours
Step-by-step explanation:
If you need to take 1 pill every 3.5 hours then this suggest that the effects of 1 pill lasts for 3.5 hours.
Therefore, if you take 4 pills then they will last: 4 x 3.5 = 14 hours
7.8+3.5(6.8)-1.5
7.8+23.8-1.5
31.6-1.5
30.1
You have to multiply 36 times 4 =144 . So you do this like this (30 times 4) +(4 times 6)= so (120)+(24)= 144. Answer is 144
