In quadrilateral PQRS above, what is the value of a2+b2 ?
The age of 15 students in a class is given below:
10, 11, 12, 10, 10, 12, 13, 13, 11, 10, 12, 11, 12, 13, 10
Find the frequency of age 13.
What is the value of (a+b)(a–b)?