Question

What is the units digit of (515)-17 (441)^13 x (717)^20)?​

Answer 1

To Find :- What is the units digit of (515)^17 * (441)^13 * (717)^20 ?

Answer :-

we know that, unit digit of a square number :-

→ 1² = 1 = unit digit 1 .

→ 2² = 4 = unit digit 4.

→ 3² = 9 = unit digit 9.

→ 4² = 16 = unit digit 6.

→ 5² = 25 = unit digit 5.

→ 6² = 36 = unit digit 6 .

→ 7² = 49 = unit digit 9.

→ 8² = 64 = unit digit 4.

→ 9² = 81 = unit digit 1.

→ 10² = 100 = unit digit 0.

Conclusion :-

• unit digit 1 in last = 1 or 9.
• unit digit 4 in last = 2 or 8.
• unit digit 6 in last = 4 or 6.
• unit digit 9 in last = 3 or 7.
• unit digit 5 in last = 5
• unit digit 0 in last = 0 .

then,

→ (515)^17 * (441)^13 * (717)^20

→ (5 in last) * (1 in last) * (7⁴ in last)

→ 5 * 1 * 1

→ 5 (Ans.)

Learn more :-

let a and b positive integers such that 90 less than a+b less than 99 and 0.9 less than a/b less than 0.91. Find ab/46

p...

https://brainly.in/question/40043888