Question

The average of seven numbers is 21. If the average of first three numbers is 19 and that of last three numbers is 20, what is the fourth number from starting

Answer 1

Answer:

30

Step-by-step explanation:

Average of the first 3 numbers= 19

Thus, their sum= 19x3= 57

Also, average of the last three numbers= 20

Thus, their sum= 20x3= 60

We have, average of all seven numbers= 21.

Thus, their sum= 21x7= 147

From these, we get the fourth number= 147-(60+57)

= 147-117= 30

Answer 2

Answer:

forth no=30

Step-by-step explanation:

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