Question

The mean of five numbers is 30. If one number is excluded, then it becomes 28. The excluded
number is

a) 28
b) 30
c) 35
d) 38​

Answer 1

Answer:

these correct answers is 38

Answer 2

Answer :

›»› The excluded number is 38.

Given :

• The mean of five numbers is 30.
• If one number is excluded, then it becomes 28.

To Find :

• The excluded number = ?

Solution :

Let us assume that, the five numbers is a, b, c, d, e.

→ Mean = (a + b + c + d + e)/5 = 30 .....(1)

→ Mean = a + b + c + d + e = 30 * 5

→ Mean = a + b + c + d + e = 150

Now, let us assume that, the excluded number is a.

→ New mean = (b + c + d + e)/4 = 28

→ New mean = b + c + d + e = 28 * 4

→ New mean = b + c + d + e = 112

Now, substitute this value in equation (1),

→ a + b + c + d + e = 150

→ a + 112 = 150

→ a = 150 - 112

→ a = 38

Hence, the excluded number is 38.

Option (d) 38 us correct ✔

Verification :

→ a + b + c + d + e = 150

→ 38 + b + c + d + e = 150

→ 38 + 112 = 150

→ 150 = 150

Here, LHS = RHS

Hence Verified !