Average of 40 numbers is 71. If the number 100 replaced by 140, then average is increased by:
A3
B4
C2
D1
Answer:
D. 1
Read Explanation:
Sum of 40 numbers = 40 × 71 = 2840
New sum of 40 numbers = 2840 – 100 + 140 = 2880
New average of 40 numbers = 2880/40 = 72
The average increased = 72 – 71 = 1