(In reply to
Puzzle Answer by K Sengupta)
a € b -> (a+1)€ (b+1) - 1, where € represents any of the four operators +,-,× and /.
In other words, one is added to each of the two numbers on the lhs, and the result is lessened by 1.
Accordingly,
13 + 10 -> (13+1) + (10+1) - 1 = 14+11-1= 24
19 - 11 -> (19+1) - (11+1) -1 = 20-12-1= 7
5 x4 -> (5+1) x (4+1) - 1 = 6x5 -1 = 30-1 = 29
Thus, we must have:
23/5 -> (23+1)/(5+1) - 1 = 24/6 -1 = 4-1= 3
Edited on March 11, 2022, 9:24 pm