The pictures too small :(
I think it would be D, about 200, because 243 is closer to 200 then it is any of the other choices
189 is 45% of 420 and 198 is 55% of 360
189 = .45x
/.45 /.45
420 = x
198 = .55x
/.55 /.55
360 = x
<span>1:50 scale means 1cm on paper and <span>50cm in real life . So 18x50=900cm
and the answer is 9m . Hope you enjoy !</span></span>
<span>Answer:
The multiplication factor of increase should be inverse of the multiplication factor of decrease.
e.g. Say you have a number 100.
You increase it by 25%. The multiplication factor is 5/4 i.e. when you multiply 100 by 5/4, you get 100*5/4 = 125. This is 25% more than 100.
Now you want to decrease it by a certain % such that you get 100 back.
Basically, 100*5/4 * x = 100
So x = 4/5 (inverse of 5/4)
Hence, you decrease by 20% (the multiplication factor of 20% is 4/5)
or
Use this formula: cumulative % change = a + b + ab/100
You want the cumulative change to be 0.
a + b + ab/100 = 0
If you know that you are increasing by 25% and want to find the % by which you should decrease to get the same number,
25 + b + 25b/100 = 0
5b/4 = -25
b = -20
So you need to decrease (hence you get the -ve sign) by 20%.</span>
