JMO - division

What is the Remainder when 231 is divided by 5?




Answer:

2³¹ = 8¹⁰ x 2 = (5 + 3)¹⁰ x 2

= (5¹⁰ + 10.5⁹.3 + ........ + 10.5.3⁹ + 3¹⁰) x 2

If 2³¹ / 5, then all the above terms are divisible except 2 x 3¹⁰

Now, the unit’s place of 3¹⁰ is 9

So, the units place is (9 x 2 = 8 – unit’s place)

So, when divided by 5 the Remainder is 3.