In 2000, the world population was 6.1 billion. In 2015, the world population was 7.3 billion. Work out the percentage increase in population. Give your answer correct to 1 decimal place.

19.7%

Step-by-step explanation:

Given that,

In 2000, the world population was 6.1 billion.

In 2015, the world population was 7.3 billion.

We need to find the percentage increase in population. The percent increase in this case is given by :

So, the increase in population is 19.7%.

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13