Question

Q3) The class marks of a class is 12 and its size is 10. The lower limit of the class is?​

Answer 1

Answer:

Let Lower Limit be L

∴ Upper Limit =L+10 [ Since, Class Width =10]

Now, we know that

ClassMark=(LowerLimit+UpperLimit)÷2

∴ (L+L+10)÷2=25 [Class Mark 25 given]

⇒ 2L+10=50

⇒ 2L=40

⇒ L=20

∴ Lower Limit of the class =20

Upper Limit of the class =20+10=30

The required class is 20−30

Answer 2

U = L + 10

(U + L ) ÷ 2 = Class mark

Therefore ,

( L + L + 10 ) ÷ 2 = 12

2L + 10 = 12 × 2

2L = 24 - 10

L = 14 ÷ 2

L = 7