Question

2+1=21,2+3=36,3+4=43, 4+5=?​

Answer 1

Answer:

420

Step-by-step explanation:

2+1=21 as digits are written in same order in the results i.e. 2 and 1

2+3=36 second digit first and then its product i.e. 2x3=6

3+4=43 this time inverting the numbers

4+5=420 as pattern is inverted

I hope you find it useful.