Question

A number was written on the board. One student increased the number by 23, but another student decreased the number by 1. The first student’s result was 7 times greater than the result of the second student. What is the number written on the board?

Answer 1

5

Explanation:

let the number written on the board be x.

1st student's number= x +23

2nd student's number= x -1

1st student's number= 7(that of the 2nd student),

x +23= 7(x -1)

x +23= 7x -7 (expand)

7x -x= 23 +7 (bring constant to 1 side)

6x= 30 (simplify)

x= 30 ÷6 (÷6 on both sides)

x= 5

Thus, the number written on the board is 5.