The weight in 1980 is
kilograms
<em><u>Solution:</u></em>
From 1980 to 1990, Lior’s weight increased by 25%
His weight is "k" kilograms in 1990
<em><u>To find: weight in 1980</u></em>
This is a percentage increase problem
Let "x" be the weight in kilograms in 1980
<em><u>The percentage increase is given by formula:</u></em>

Here,
Initial value in 1980 = x
Final value in 1990 = k
Percentage increase = 25 %
<em><u>Substituting the values in formula,</u></em>

Thus the weight in kilograms in 1980 is 
Answer:
1.1.1- Michael has 200 lovebirds in total
1.1.2- There are 40 birds in each cage
1.1.3- 120/80 = 3/2
Step-by-step explanation:
120+80=200
200÷5=40
120÷40=3, 80÷40=2
Answer:
I will answer in a general way because the options are not given.
We know that the area of model A is smaller than the area of model B.
For model A, we have 72 shaded sections, out of 100.
Then the quotient of model A is:
72/100 = 0.72
For model B we have 10 sections, and x shaded ones.
Because model B is greater than model A, we know that:
x/10 should be larger than 72/100
then we have the inequality:
x/10 > 0.72
x > 0.72*10
x > 7.2
And we can not have more than 10 shaded sections (because there is a total of 10 sections) then:
10 ≥ x > 7.2
Then x can be any whole number in that interval.
the possible values of x are:
x = 8
x = 9
x = 10
15 - 7 = 8 so there are many you can do like:
16 - 8 = 8
20 - 12 = 8
22 - 14 = 8
and so on, there are many.