# Two sets

Suppose Set B contains 69 elements and the total number elements in either Set A or Set B is 124. If the Sets A and B have 29 elements in common, how many elements are contained in set A?

Correct result:

A =  55

#### Solution:

$B=69 \ \\ AB=A\cap B \ \\ AB=29 \ \\ B_{1}=B - AB=69 - 29=40 \ \\ T=124 \ \\ \ \\ A=T - AB - B_{1}=124 - 29 - 40=55$

Our examples were largely sent or created by pupils and students themselves. Therefore, we would be pleased if you could send us any errors you found, spelling mistakes, or rephasing the example. Thank you!

Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...):

Be the first to comment!

## Next similar math problems:

• Disjoint
How many elements have union and intersection of two disjoint sets when the first have 1 and secodn 8 elements.
• 80 students
80 students were asked what type of test they preferred. 50 students said they liked multiple choice and 42 liked true or false. If 36 liked both multiple choice and true or false types, how many students preferred multiple choice only?
• TVs
Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase.
• Gloves
I have a box with two hundred pieces of gloves in total, split into ten parcels of twenty pieces, and I sell three parcels. What percent of the total amount I sold?
• Number
What number is 20 % smaller than the number 198?
• Equation
Solve the equation: 1/2-2/8 = 1/10; Write the result as a decimal number.
• Unknown number
Identify unknown number which 1/5 is 40 greater than one tenth of that number.
• MO 2016 Numerical axis
Cat's school use a special numerical axis. The distance between the numbers 1 and 2 is 1 cm, the distance between the numbers 2 and 3 is 3 cm, between the numbers 3 and 4 is 5 cm and so on, the distance between the next pair of natural numbers is always i
• Sales off
Goods is worth € 70 and the price of goods fell two weeks in a row by 10%. How many % decreased overall?
• Base, percents, value
Base is 344084 which is 100 %. How many percent is 384177?
• Apples 2
James has 13 apples. He has 30 percent more apples than Sam. How many apples has Sam?
• Class
In a class are 32 pupils. Of these are 8 boys. What percentage of girls are in the class?
• The percentages in practice
If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fr
• Down syndrome
Down syndrome is one of the serious diseases caused by a gene mutation. Down syndrome occurs in approximately every 550-born child. Express the incidence of Down's syndrome in newborns at per mille.
• Inequation
Solve the inequation: 5k - (7k - 1)≤ 2/5 . (5-k)-2
• New refrigerator
New refrigerator sells for 1024 USD, Monday will be 25% discount. How much USD will save, and what will be the price?
• Simplify 2
Simplify expression: 5ab-7+3ba-9