Search found 4 matches


Re: Units digit?

For 33^43,
Cyclicity of powers of units digit of 33 i.e. 3 is 4, i.e. 3, 9, 7, 1. So, 43=4*10+3.

Third power of 3 will end in 7.

For 43^33.
33=4*8+1.

First power of 3 ends in 3.

Thus, units digit of the sum of 7 and 3 will be 0.

by rohanraj

Wed Apr 28, 2021 11:37 pm
Forum: Problem Solving
Topic: Units digit?
Replies: 5
Views: 3319

Re: if Y is the smallest positive integer (no. properties)

3150=5*5*3*3*7*2.

So, to make it a perfect square, the least no to be multiplied will be 7*2=14.

by rohanraj

Wed Apr 28, 2021 11:30 pm
Forum: Problem Solving
Topic: if Y is the smallest positive integer (no. properties)
Replies: 7
Views: 3897

Numbers

† and ¥ represent nonzero digits, and (†¥)² - (¥†)² is a perfect square. What is that perfect square?

A. 121
B. 361
C. 576
D. 961
E. 1089

by rohanraj

Wed Apr 28, 2021 11:25 pm
Forum: Problem Solving
Topic: Numbers
Replies: 0
Views: 236