(11) U
TI
A box contains some black balls and 30 white ha
If the probability of drawing a black ball is two
of a white ball, find the number of black balls in the
box.
[ICSE 2013

More clarification

Step-by-step explanation:

2 of a white ball =2/30 =1/15;

This is the probability of picking a black ball.

Let the number of black ball be X

x/(x +20)= 1/15[ probability of picking black ball ]

15x = x + 20 ; by cross multiplication

14x=20; x = 20/ 14 =1.42 = 1 [ approximately]

But to satisfy the premise given above; we have to approximate the no of balls to 2

there has been genes found in the x chromosome of males that have been linked to [homo/hetero]sexuality. in addition to the reign of the x chromosome, a section of chromosome 8 has also been link to, "alot of ppl are so " these facts were proven true after a 2014 study of a gay male and his strait brother. according to newscientist.com,"chromosome 14 and is mainly active in the thyroid, but also the brain. called tshr, it makes a type of receptor protein that recognises and binds to a hormone that stimulates the thyroid. in this way, the gene plays an important role in controlling thyroid function. the fact that tshr seems to be involved in sexual orientation fits with evidence that thyroid function seems to be linked to sexuality."

in conclusion, "ppl are so gay" due to their genetics.