Solution of 48÷8(14-8)=?;Tricky problems ;Can you solve this?#Railway RRB NTPC ;Reasoning

The solution of 8x=6(mod14) is

Solve the equation.14y-8=13

x^(2)+10^(-8)x-10^(-14)=0 How to solve ?

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

Assertion (A ) : At 25^(@)C , the pH of 1 xx 10^(-8) M solution of hydrochloric acid is 8 Reason (R ) : Ph of acidic solution is always below 7 at 25^(@)C