Question

A square of nine numbers is marked in a calendar. The sum of all
these numbers is 90. What are the numbers?7​

Answer 1

Answer:

Hi

Step-by-step explanation:

Divide the sum (90) by the number of figures (9), you find 10.

the center line of the square will be a row of three numbers with 10 in the middle, i.e. 9 10 11. Its sum is three times 10 (because 9 + 11 = 2 * 10).

That is all. Pick any calendar month whereby 10 is not on a side, and select the square of numbers where 10 in in the center place. Example: October 2018, where 10 is a Wednesday. The square will be Tu We Th on three consecutive lines with 10 in the middle.

2 3 4 Sum of row: 9

9 10 11 Sum of row: 30

16 17 18 Sum of row: 51

Sum of all three rows: 90 QED

Answer 2

Step-by-step explanation:

Let the nine number in the calender are:

x

x + 1

x + 2

x + 7

x + 8

x + 9

x + 14

x + 15

x + 16

sum = 9x + 72 = 90

x = 90 - 72 ÷ 9 = 18 ÷ 9 = 2

The numbers in the calender are ;

2,3,4

9,10,11

16,17,18