The pie diagram shows percentage of persons according to the blood group. Answer the following question find the measurement of central angle for blood group $A$.

Q. In a class there are 60 students. The following pie diagram shows the number of students according to blood-group. There are 8 students having blood-group A, 18 students having blood-group O. Students having B group are represented by ${120}^o$, find the number of students having AB blood-group :

Q. A person with blood group A can (a) donate blood to, and (b) receive blood from,

Q. A person with blood group 'A' can donate blood to the persons with blood group 'AB' because it

Q. Which of the following statement is incorrect ?
(a) A person of 'O' blood group has anti 'A' and anti 'B' antibodies in his blood plasma.
(b) A person of 'B' blood group can't donate blood to a person of 'A' group
(c) Blood group is designated on the basis of the presence of antibodies in the blood plasma.

Q. The blood of AB group donor can be transfused to a person with which of the following blood groups?