Answer:
1445
Step-by-step explanation:
Answer: 5 Erasers
Step-by-step explanation: It's quite simple, really. You divide 20 by 4, (the number of pencils and the ratio number) and then you multiply whatever the quotient was by the ratio number for erasers.
Let t=number of years since 1991.
Then
P(t)=147 e^(kt) ... in millions
P(0)=147 e^(0)=147
P(7)=147 e^(7k)=153
e^(7k)=(153/147)
take ln both sides
ln(e^(7k))=ln(153/147)
7k=0.0400 => k=0.005715
Year 2017=>t=2017-1991=26
P(26)=147e^(26*.005715)=170.55
Answer: in 2017, the projected population is 170.55 millions.
It really depends what you're understanding or how the problem is set up.