Advertisements
Advertisements
प्रश्न
In a school, students decided to plant trees in and around the school to reduce air pollution. It was decided that the number of trees, that each section of each class will plant, will be double of the class in which they are studying. If there are 1to 12 classes in the school and each class has two sections, find how many trees were
planted by the students. Which value is shown in this question?
उत्तर
Solution:-
Class 1 plant trees = 2 x class 1 x 2 section = 2 x 1 x 2 = 4 x classs= 4 x 1 = 4 trees
Class 2 plant trees = 4 x classs = 4 x 2 = 8 trees a = 4
d = 8
n = 12
S12 = 12/2[2x4 + 11x4] = 312 trees
APPEARS IN
संबंधित प्रश्न
A number x is selected at random from the numbers 1, 2, 3, and 4. Another number y is selected at random from the numbers 1, 4, 9 and 16. Find the probability that product of x and y is less than 16.
Two dice are thrown. Find the probability of getting :
1) The sum of the numbers on their upper faces is at least 9.
2) The sum of the numbers on their upper faces is 15.
3) The number on the upper face of the second die is greater than the number on the upper face of the first die.
A target shown in Fig. below consists of three concentric circles of radii, 3, 7 and 9 cm
respectively. A dart is thrown and lands on the target. What is the probability that the dart will land on the shaded region?
A box contains cards bearing numbers from 6 to 70. If one card is drawn at random from the box, find the probability that it bears
(i) a one digit number.
(ii) a number divisible by 5.
(iii) an odd number less than 30.
(iv) a composite number between 50 and 70.
Choose the correct alternative answer for the following question.
What is the probability of the event that a number chosen from 1 to 100 is a prime number ?
A bag contains cards numbered from 1 to 49. A card is drawn from the bag at random, after mixing the card thoroughly. Find the probability that the number on the drawn card is an even prime number
Cards numbered from 11 to 60 are kept in a box. If a card is drawn at random from the box, find the probability that the number on the drawn card isa prime number less than 20
If two different dice are rolled together, the probability of getting an even number on both dice is
A number is selected at random from the numbers 1 to 30. The probability that it is a prime number is
A card is drawn at random from a well-shuffled pack of 52 cards. Find the probability that the drawn card is neither a king nor a queen.
Two different dice are tossed together. Find the probability that the number on each die is even.
A game of chance consists of spinning an arrow which is equally likely to come to rest pointing to one of the numbers 1, 2, 3,..., 12 as shown in the figure. What is the probability that it will point to a number which is a multiple of 5?
A box contains 80 discs, which are numbered from 1 to 80. If one disc is drawn at random from the box, find the probability that it bears a perfect square number.
A die is thrown once. The probability of getting an even number is
By using two variables, write the following statement in mathematical form:
The cost of two tables and five chairs is 2,200.
A bag contains 3 white, 5 black, and 2 red balls, all of the same shape and size. A ball is drawn from the bag without looking into it, find the probability that the ball drawn is not a red ball.
In a single throw of a die, find the probability of getting :
(i) 8
(ii) a number greater than 8
(iii) a number less than 8
Two dice are rolled, find the probability that the sum is less than 13
In the experiment of tossing a coin one time, the outcome is either ______ or ______.
Three coins are tossed simultaneously. What is the probability of getting at most one tail?
