Question

(7×7×7×…×7). Here, there are 7 for 21 times. What will be the remainder if the product is divided by 10? with steps

Answer 1

Answer:

If you look at the power of 7, it shows a repeated trend at the Unit's digit. For e.g.:

7^1 = 7 (7 at unit place)

7^2 = 49 (9 at unit place)

7^3 = 343 (3 at unit place)

7^4 = 2401 (1 at unit place)

7^5 = 16807 (7 at unit place)

So if you see, this trend of 7,9,3,1......7,9,3,1.......repeats itself.

7^21 will give 3 as unit's digit and when it is divided by 10, it will give the remainder as 3.

★ So, Answer will be 3

Answer 2

⤵⤵Your Answer⤵⤵

7 × 7 × 7 × 7......... 21 Times

= 147

= 147 ÷ 7 = 21

= 21 ÷ 7 = 3

= 3

so, 3 is Your Answer