Numbers

Practice Numbers – What is the greatest positive power of 5 that divides 30! exactly?

Practice Numbers – If a and b are natural numbers and a-b is divisible by 3, then a³-b³ is divisible by:

Practice Numbers – The number nearest to 15207, which is divisible by 467, is:

Practice Numbers – Which of the following numbers is exactly divisible by 24 ?

Practice Numbers – What least value must be assigned to * so that the number 63576*2 is divisible by 8?

Practice Numbers – What is the unit digit in 27²⁰ ?

Practice Numbers – If N = 82^3 – 62^3 – 203 then N is divisible by:

Practice Numbers – A company installed 36 machines at the beginning of the year. In March they installed 9 additional machines and then disconnected 18 in August. How many were still installed at the end of the year.

Practice Numbers – The number of diagonals of a polygon having 38 sides is:

Practice Numbers – The cost of four dozen proof machine ribbons and five dozen accouting machine ribbons was Rs.160/-. If one dozen accounting machine ribbons cost Rs.20/-, what is the cost of a dozen proof machine ribbons?

Practice Numbers – The number of diagonals of a polygon having 22 sides is:

Practice Numbers – A tape manufacturer reduces the price of his heavy duty tape from Rs.30/- to Rs.28/- a reel and the price of a regular tape from Rs.24/- to Rs.23/- a reel. A computing centre normally spends Rs.1440/- a month for tapes and 3/4 of this is for heavy duty tapes. How much will they save a month under the new prices?

Practice Numbers – When three times a number is added to the square of the given number, the result is 54. What is the number?

Practice Numbers – When five times a number is added to twice the square of the same number, the result is 102. What is the number?

Practice Numbers – If “a”, “b” and “c” are distinct positive real numbers then determine the value of the following expression.

(a2 (b + c) + b2 (c + a) + c2 (a + b))/abc