Question

The value of the last digit of a 3-digit number
is two times the first digit and three times the
middle digit. Find the 3-digit number​

Answer 1

Step-by-step explanation:

Let the number be 100x+10y+z

(i) x+z=2y and (ii) z-y=4x . Now, (i)−(ii)⇒x+y=2y−4x⇒y=5x. (i)−(ii)⇒x+y=2y−4x⇒y=5x. Putting x= = 1 we get y=5 and this is the only admissible value of y (since other mutiples of x will make y disqualified as a digit). Again when x=1,y=5andz=4x+y=9. x=1,y=5andz=4x+y=9. So, the number is 159 and the middle digit is 5.