The probability of drawing a black marble is 7/31 or .226 or 22.581%. To find the probability of these type of questions, add all together to get 31, then since there are 7 black marbles the probability would be 7/31.

6 0

1 year ago

If one root of the equation is 4x^2- 2x+p-4 be the reciprocal of other. then find the value of p

SashulF [63]

Answer:

p = 8

Step-by-step explanation:

Let one root of the eqn. be alpha . Other root is 1/alpha .

We know that product of both roots of an quadratic eqn. is c/a where "c" is the co-efficient of the constant & "a" is the co-efficient of x^2.

Here "c" is p-4 & "a" is 4. And the product of roots is 1 ( ∵ prdouct of a number and its reciprocal is 1 )

$\frac{c}{a} = 1\\=> \frac{p - 4}{4} = 1\\=> p - 4 = 4\\=> p = 4 + 4 = 8$

5 0

3 years ago