Recent questions and answers in Elementary Number Theory

2 2 votes
2 2 answers
156
156 views
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason RAssertion A: The order of the group ( $\mathrm{Z}_{5}, \times$ ) divid...
0 0 votes
2 2 answers
300
300 views
The remainder obtained when $\sum\limits_{m=1}^{2025} m!$ is divided by $18$ is$7$$9$$12$$16$
1 1 vote
3 3 answers
428
428 views
The number of factors of $2025$ (including $1$ and itself) equals$15$$25$$35$$45$ 
0 0 votes
1 1 answer
260
260 views
Let $b_{n} b_{n-1} \cdots b_{1}$ be the decimal representation of an $n$ digit number $m$. Let $b_{n} b_{n-1} \cdots b_{2}$ be the integer $a$ obtained from $m$ by stripp...
0 0 votes
3 3 answers
367
367 views
Consider the given number $(45)_{y}$ where $y$ is the base of the number. Some of the possible values of $y$ are given below.$5$$6$$7$$8$Choose the correct answer from th...
0 0 votes
1 1 answer
244
244 views
Let $m$ and $n$ are positive integers. ThenIf $n \neq 1$, then $m<mn$If $k$ is composite, then $k=m n$ where $1<m, n>k$If $mn=1$, then $m=1$ and $n=1$.If $k$ is composite...
0 0 votes
0 0 answers
176
176 views
Arrange the following in ascending order :Remainder of $49^{16}$ when divided by $17$Remainder of $2^{446}$ when divided by $9$Remainder of $155^{17}$ when divided by $17...
1 1 vote
1 1 answer
548
548 views
What is the smallest positive integer that when multiplied with $2^{3} 3^{2} 4^{3} 5^{7} 6^{5}$ results in a perfect square?$6$$10$$15$$60$$210$ 
0 0 votes
1 1 answer
412
412 views
How many distinct factors does $2^{2} 3^{3} 4^{4} 5^{5}$ have? For example, $12$ has $6$ distinct fact ors: $1,2,3,4,6$, and $12$.$240$$264$$324$$360$None of the above 
0 0 votes
1 1 answer
283
283 views
For any positive integer $d$, the set\[\left\{10^{a}-10^{b} \mid a, b \text { are distinct positive integers }\right\}\]contains a multiple of $d$.
0 0 votes
1 1 answer
227
227 views
How many positive integers less than $1000$ are neither divisible by $3$ nor divisible by $5$? Explain how you arrived at your answer.
1 1 vote
0 0 answers
172
172 views
A sequence of five natural numbers $s_{1} \leq s_{2} \leq s_{3} \leq s_{4} \leq s_{5}$ satisfy the following conditions: $\sum\limits_{i=1}^{5} s_{i}=35$$\sum\limits_{i=1...
0 0 votes
0 0 answers
331
331 views
For a positive integer $m$, let $d(m)$ denote the number of divisors of $m$, including $1$ and $m$. Define a sequence $\left\{a_{n}\right\}_{n=1}^{\infty}$ by\[a_{n}=\#\{...
0 0 votes
1 1 answer
279
279 views
Let $b_{n} b_{n-1} \cdots b_{1}$ be the decimal representation of an $n$ digit number $m$. Let $b_{n} b_{n-1} \ldots b_{2}$ be the integer $a$ obtained from $m$ by stripp...
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