A = a+b/2 x h
Add sides a and b then divide by 2
After that multiply by the h
Given that the number is x,
10% increase will give us a new number of:
110/100*x
=1.1x
10% decrease will give us a new number of:
90/100*1.1x
=0.99x
This implies the new number is less than the original number
Find answer is the given attachment
Answer:
Step-by-step explanation:
Given that there are 3 sets such that there are 100 elements in A1, 1000 in A2, and 10,000 in A3
a) If A1 ⊆ A2 and A2 ⊆ A3
then union will contain the same number of elements as that of A3
i.e. 
b) If the sets are pairwise disjoint.
union will contain the sum of elements of each set

c) If there are two elements common to each pair of sets and one element in all three sets
We subtract common elements pairwise and add common element in 3
i.e. 