The solution 574 (two parts) is correct. Excellent, bobbym!
575. All the three face cards of spades are removed from a well-shuffled pack of 52 cards. A card is drawn at random from the remaining pack. Find the probability of getting
(i) a black face card
(ii) a queen
(iii) a black card
The solutions 572(i) and 572(ii) are correct. Excellent, bobbym!
573. Water is flowing through a cylindrical pipe, of internal diameter 2 cm, into a cylindrical tank of base radius 40 cm, at the rate of 0.4 cm m/s. Determine the rise in level of water in the tank in half an hour.
The solution #6072 is correct. Excellent, bobbym!
#6073. A number is chosen at random from among the first 30 natural numbers. The probability of the number chosen being prime is ________.
#6074. A card is drawn at random from a well shuffled pack of 52 playing cards. The probability of getting a red face card is ________.
The solution 571 is correct. Excellent, bobbym!
572. (i) A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random. What is the probability that the marble taken out will be
(iii) not green?
572. (ii) There are 30 cards, of same size, in a bag on which numbers 1 to 30 are written. One card is drawn out of the bag at random. Find the probability that the number on the selected cards divisible by 3.
The solution 569 is correct. Neat work, bobbym!
570. From a point 100 m above a lake, the angle of elevations of a stationary helicopter is 30 degrees and the angle of depression of reflection of the helicopter in the lake is 60 degrees. Find the height of the helicopter.