Number System, Problems on Number

How many prime numbers are there between 50 and 60?

A positive number, when decreased by 4, is equal to 21 times the reciprocal of the number. The number is:

The price of commodity X increases by 40 paisa every year, while the price of commodity Y increases by 15 paisa every year. If in 2001, the price of commodity X was Tk 4.20 and that of Y was Tk. 6.30, in which year commodity X will cost 40 paisa more than the commodity Y?

The difference between a number and its square is 72. What is the number?

A school has 10 classes with the same number of students in each class. One day, the weather was bad and many students were absent. 3 classes were half full. 5 classes were 3/4 full and 2 classes were 1/6 empty. A total of 74 students were absent. What is the total number of students in this school?

If the summation of roots of two integers is √(11+8√2). What is the summation of the squares of these two integers?

If x and y are two different real Numbers and xz = yz then the value of z is?

The sum of squares of two numbers is 48 and the square of their difference is 16. The product of the two number is:

A forester wants to plant 66 coconut trees, 88 date trees and 110 plum trees in equal sized rows (in terms of number of tress). Also he wants to make distinct rows of trees (i.e only one type of trees in one row). What is the minimum number of rows required?

Salim sells 900 shares via his broker who charges a flat rate of commission of Tk. 20 on all transmission of less than Tk. 1600. His bank account is credited with Tk. 340 from the share sale. What price were his shares sold at?

If a+b+c = 12, a+b = 4, and a+c = 7, what is the value of a?

40 is subtracted from 60% of a number, the result is 50. Find the number?

If Kamal gves 20 marbles to Shuvo, then, both of them will have equal numbers of marbles in their possessions. If Shovo gives 40 marbles to Kamal then Kamal will have twice the number of marbles that Shuvo will retain. What is the number of marbles that Kamal has?

When 9 is added to one fourth of a number, the result is 19. What is the number?

A number is as much greater than 36 as is less than 86. Find the number.

48.95 - 32.006 = ?

A number is doubled and 9 is added. If the resultant is trebled, it becomes 75. What is that number?

If 5 > x > 2 and 10 > y > 7, then which of the following expression must be positive?

Which of the following is a prime number? 

The difference between number and its three-fifth is 50. What is the number?