Question

Find the squares of the following numbers containing 5 in unit's place.
(i) 15
(ii) 95
(iii) 105
(iv) 205
full ans by solving​

Answer 1

Formula = a5=(a*a+1)5^2
1. (1*2)5^2 =225
2.(9*10)5^2=9025
3.(10*11)5^2=11025
4.(20*21)5^2=42025