a box contains 20 electric bulbs , out of which 4 are defective . 2 bulbs are chosen at random from this box . The probability that at least one of these is defective is

There is a rectanguler parking lot with a length of 2x and a width of x. What is the ratio of the perimetr of...

The ratio of income of a to that of B is 7:5 and the expenditure of A to that of B is 3:2. If , at the end of...

An empty backet being filled with paint at a constant rate takes 6 min to be filled to 7/10 of its capacity ....

In distributing milk at a summer camp it is found that a quart of milk will fill either 3 large glass tumblers...

a bank offers 5% interst compounded half yearly . A customer deposit tk.1600 each on 1st july of a year . At t...

a box is made in the form of a cube. IF a second cubical box has inside first box , how many times as much doe...