Question

The average of 5 numbers is 64. If the first four numbers are 40, 50, 60 and 70, then find the fifth number.​

Answer 1

Answer:

let fifty number be x

average = sum of all number / toal number

64 = (40+50+60+70+x) / 5

320= 220+x

x= 320-220

x= 100

the fifth no is 100

Answer 2

Step-by-step explanation:

AVERAGE OF 5 NUMBERS = 64

FIRST FOUR NUMBERS = 40 , 50 , 60 , 70

FIFTH NUMBER = X

64 = 40 + 50 + 60 + 70 + X / 5

64 × 5 = 220 + X

320 = 220 + X

320 - 220 = X

100 = X

HENCE , THE FIFTH NUMBER IS 100

MEAN = 40 + 50 + 60 + 70 + 100 / 5

= 320 / 5

= 64

IT MEANS MY ANSWER IS CORRECT .