Number System, Problems on Number

The average of a, b, c is б and a - b = 4, ab = 21; What is the value of c?

If xy < 0, which of the following must be true?
i. x + y = 0 ii. 2y - 2x < 0, iii. x² + y²> 0

√(16 + 16) =?

The H.C.F of two numbers is 24. The number which can be their L.C.M is-

Rohit is 28th from the left end of a row of 50 students and Shyam is 28th from the right end of the row. How many students are sitting between them?

Find the multiple of 11 in the following numbers.

If m is an even integer and n is an integer (either odd or even), then which of the following will always be even?
i) m² + n² + n        ii) (m - n)(n + 1)           iii) m² - n² + 1

The value of p for which equation x² + (p – 3)x + p = 0 has real and equal roots is-

How many cases do you need if you have to pack 112 pairs of shoes into cases that each hold 28 shoes?

How many integers between 1 and 100 are divisible by 3 but not by 5?

If 3/p = 6 and 3/q = 15 then p - q = ?

The difference between two numbers is 5 and the difference between their squares is 65. What is the larger number?

In a row in the theatre the seats are numbered consecutively from T1 to T50. Sumon is sitting in seat T17 and Shihab is still sitting in seat T39. How many seats are there between them?

If p and q are positive integers with pq = 36, then p/q cannot be.

Find the least number of five digits which when divided by 40, 60 and 75, leave remainders 31, 51 and 66 respectively.

Half the people on a bus get off at each stop after the first and no one gets on after the first stop. If only one person gets off at stop number 7, how many people got on at the first stop?

Which of the following is the lowest positive integer that is divisible by 8, 9, 10, 11 and 12?

How many integers from 1 to 1000 are divisible by 30 but not by 16?

Find the LCM of (1 - a)², (1 - a), (a - 1)².

The least number which should be added to 2,497 so that the sum is exactly divisible 5, 6, 4 and 3 is