Best trick For problem of Electrostatic(a new concept), solve problems like this in 1 min.

An exam consists of 3 problems selected randomly from a collection of 10 problems. For a student to pass, he needs to solve correctly at least two of three problems. If the student knows to solve exactly 5 problems, then the probability that the students pass the exam is

A student can solve 2 out of 4 problems of mathematics, 3 out of 5 problem of physics, and 4 out of 5 problems of chemistry. There are equal number of books of math, physics, and chemistry in his shelf. He selects one book randomly and attempts 10 problems from it. If he solves the first problem, then the probability that he will be able to solve the second problem is 2//3 b. 25//38 c. 13//21 d. 14//23

A computer solved several problems in succession. The time it took to solve each successive problem was the same number of times smaller than the time it took to solve the preceding problem. How many problems were suggested to the computer if it spent 63.5 min to solve all the problems except for the first, 127 min to solve all the problems except for the last one, and 31.5 min to solve all the problems except for the first two?

For an initial screening of an admission test, a candidate is given fifty problems to solve. If the probability that the candidate can solve any proglem is (4)/(5) , then the probability that he is unable to solve less than two problem is

A can solve 90% of the problems given in a book and B can solve 70%. What is the probability that at least one of them will solve the problem, selected at random from the book?

Trick for Newton's laws of Motion (advanced problems) in very unique way.

Given the probability that A can solve a problem is 2/3 and the probability that B can solve the same problem is 3/5. Find the probability that none of the two will be able to solve the problem.

One boy can solve 60% of the problem in a book and another can solve 80% . The probability that at least one of the two can solve a problem chosen at random from the book is .

A problem in mathematics is given to three stdents A,B,C and their chances of solving the problem are 1/2 , 1/3 and 1/4 respectively . The probability that the problem is solved is

Three persons work independently on a problem. If the respective probabilities that they will solve it are 1/3, 1/4 and 1/5, then find the probability that not can solve it.