1 votes
1 answer
2041
Let $a_{1},a_{2}\dots$ be integers such that $a_{1}-a_{2}+a_{3}-a_{4}+\dots+(-1)^{n-1}a_{n}=n$, for all $n\geq 1$ Then $a_{51}+a_{52}+\dots+a_{1023}$ equals$-1$$10$$0$$1$...
1 votes
1 answer
2043
In a triangle $\text{ABC}$, medians $\text{AD}$ and $\text{BE}$ are perpendicular to each other, and have lengths $12$ cm and $9$ cm, respectively. Then, the area of tria...
4 votes
1 answer
2046
How many factors $2^{4}\times3^{5}\times10^{4}$ are perfect squares which are greater than $1$ _______
1 votes
1 answer
2047
What is the largest positive integer $n$ such that $\frac{n^{2}+7n+12}{n^{2}-n-12}$ is also a positive integer?$8$$12$$16$$6$
1 votes
1 answer
2048
Let $a,b,x,y$ be real numbers such that $a^{2}+b^{2}=25,x^{2}+y^{2}=169$, and $ax+by=65$. If $k=ay-bx$, then$k=0$$0< k\leq \frac{5}{13}$$k=\frac{5}{13}$$k \frac{5}{13}$
1 votes
1 answer
2049
Let $A$ be a real number. Then the roots of the equation $x^{2}-4x-\log _{2}A=0$ are real and distinct if and only if$A \frac{1}{16}$$A \frac{1}{8}$$A< \frac{1}{16}$$A< \...
1 votes
1 answer
2052
1 votes
1 answer
2054
Let $\text{ABC}$ be a right-angled triangle with hypotenuse $\text{BC}$ of length $20$ cm. If $\text{AP}$ is perpendicular on $\text{BC}$, then the maximum possible lengt...
2 votes
1 answer
2055
The base of a regular pyramid is a square and each of the other four sides is an equilateral triangle, length of each side being $20$ cm. The vertical height of the pyram...
1 votes
1 answer
2056
Let $f$ be a function such that $f (mn) = f (m) f (n)$ for every positive integers $m$and $n$. If $f (1), f (2)$ and $f (3)$ are positive integers, $f (1) < f (2),$ and $...
1 votes
1 answer
2057
1 votes
1 answer
2058
If $5^{x}-3^{y}=13438$ and $5^{x-1}+3^{y+1}=9686$, then $x+y$ equals _______
1 votes
1 answer
2060
The number of common terms in the two sequences: $15, 19, 23, 27,\dots,415$ and $14, 19, 24, 29,\dots,464$ is$18$$19$$21$$20$
3 votes
1 answer
2063
The value of the sum $7 \times 11 + 11 \times 15 + 15 \times 19 + \dots$ + $95 \times 99$ is$80707$$80773$$80730$$80751$
3 votes
1 answer
2064
How many two-digit numbers, with a non-zero digit in the units place, are there which are more than thrice the number formed by interchanging the positions of its digits?...
2 votes
1 answer
2065
3 votes
1 answer
2069
A chord of length $5$ cm subtends an angle of $60^\circ$ at the centre of a circle. The length, in cm, of a chord that subtends an angle of $120^\circ$ at the centre of t...
2 votes
1 answer
2070
Let $f\left (x \right ) = \max\left \{5x, 52 – 2x^{2}\right \}$ , where $x$ is any positive real numbers. Then the minimum possible value of $f(x)$ is ________
2 votes
1 answer
2073
If $a$ and $b$ are integers such that $2x^{2}- ax + 2 0$ and $x^{2}-bx+8 \geq 0$ for all real numbers $x$, then the largest possible value of $2a-6b$ is _________
2 votes
1 answer
2075
If $\text{N}$ and $x$ are positive integers such that $\text{N}^{\text{N}}=2^{160}$ and $\text{N}^{2} + 2^{\text{N}}$ is an integral multiple of $2^{x}$, then the largest...
2 votes
1 answer
2076
Let $t_{1}, t_{2},\dots$ be a real numbers such that $t_{1}+t_{2}+\dots+t_{n}=2n^{2}+9n+13$, for every positive integers $n\geq2$.If $t_{k}=103$ , then $k$ equals
3 votes
1 answer
2077
If $p^{3}=q^{4}=r^{5}=s^{6}$, then the value of $\log_{s}\left ( pqr \right )$ is equal to $16/5$$1$$24/5$$47/10$
4 votes
2 answers
2079