Brothers and sisters

There are 35 children in the class, 23 of them have a brother, and 27 of them have a sister. How many children have both a brother and a sister when there are 5 children in the class who have no brother or sister?

Correct result:

x =  20

Solution:

$$\begin{gathered} 30=x+27-x+23-x \\ x=23+27-(35-5)=20 \end{gathered}$$

Try another example

Showing 0 comments:

Next similar math problems:

• Family
  A man and a woman have 6 daughters together (or - "with each-other" so that step-children are excluded). Each daughter has one brother. How many members are in the immediate family?
• Camp
  In a class are 26 children. During the holidays 16 children were in the camps and 14 children on holiday with their parents. Determine the minimum and maximum number of children that may have been in the camp and on holiday with their parents at the same
• Family
  Martin has just as brothers as sisters. His sister Jana but has 2 times more brothers than sisters. a) How many children are in this family? b) How many boys and how many girls are in the family?
• Christmas or Easter
  Please calculate this example by the Venn equation. They asked 73 students whether they like Christmas or Easter. 34 of them like one of the holidays. 39 loves Easter. There are twice as many students who wish both holidays than those who only love Easter
• Math logic
  There are 20 children in the group, each two children have a different name. Alena and John are among them. How many ways can we choose 8 children to be among the selected A) was John B) was John and Alena C) at least one was Alena, John D) maximum one wa
• Italian writer
  There were 17 children in the barracks with an Italian writer. 6 children ordered a book in an Italian original and 12 children in the translation. How many children ordered a book in both languages if the three children did not order it?
• Brothers and sisters
  Lenka has as many brothers as sisters. Her brothers have twice as many sisters as brothers. How many brothers and sisters are in the family?
• Two sisters
  Two sisters together have 54 CDs. 6/8 CDs has younger sister and is equal to 3/5 of CDs older sisters. How many CDs has each of the sisters?
• Pupils
  There are 27 pupils in the classroom. They can swim 21 and ski nine pupils. Neither swim nor ski three pupils. How many pupils can swim and ski?
• Holidays
  Of the 35 students of class were 7 on holiday in Germany and just as much in Italy. 5 students visited Austria. In none of these countries was 21 students, all three visited by one student . In Italy and Austria were 2 students and in Austria and Germany
• Large family
  I have as many brothers as sisters and each my brother has twice as many sisters as brothers. How many children do parents have?
• Jane and Miro
  Jane brother Miro is 42 years. And he is three times old as it was Jane when Miro was for so many years as there are now Jane. How old is Jane?
• Sheep
  Shepherd tending the sheep. Tourists asked him how much they have. The shepherd said, "there are fewer than 500. If I them lined up in 4-row 3 remain. If in 5-row 4 remain. If in 6-row 5 remain. But I can form 7-row." How many sheep have herdsman?
• Family 8
  Father is 38 years old, daughter 12, son 14. How many years will father have as many years as his children together?
• School trip
  On a school trip, 17 of the 28 children bought ice cream or chocolate in a candy store. Twelve children bought chocolate, and nine children bought ice cream. How many children bought ice cream and chocolate? How many children did not buy ice cream? How ma
• Four classses
  Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
• Three excursions
  Each pupil of the 9A class attended at least one of the three excursions. There could always be 15 pupils on each excursion. Seven participants of the first excursion also participated in the second, 8 participants of the first excursion, and 5 participan