Find the unit digit of the equation. 312 + 322 + 332 + 342 + 352 + 362 + 372 + 382 + 392
5
Given:
312 + 322 + 332 + 342 + 352 + 362 + 372 + 382 + 392
Calculation:
Unit digit of the given equation
⇒ Unit digit (12 + 22 + 32 + 42 + 52 + 62 + 72 + 82 + 92)
⇒ Unit digit (1 + 4 + 9 + 6 + 5 + 6 + 9 + 4 + 1)
⇒ Unit digit (45)
∴ The unit digit of the given expression = 5
Alternate Method
Unit digit of 312 + 322 + 332 + 342 + 352 + 362 + 372 + 382 + 392
⇒ [9(9 + 1)(18 + 1)/6 unit digit
⇒ (3 × 5 × 19) unit digit
Unit digit = 5
∴ The unit digit of the given expression = 5
Important Questions from Unit Digit
The unit digit in 4 × 38 × 764 × 1256 is:
How many times does the number 3 occur in unit's place for numbers ranging from 1 to 100?
A. 20
B. 11
C. 10
D. 19
Find the unit digit in the given factor (3451) 51 × (531) 43 .
A. 6
B. 4
C. 1
D. 9
What is the unit digit of 178 × 593 + 157?
Find the unit digit of $(123)^{123} \times (347)^{347} \times (568)^{568}$.
