Assuming that the probability of boys and girls is equal (in reality slightly more boys than girls are born), the probability is 1/2, simply because the older girl's gender is given and therefore not a part of the probability.
This question comes from the 'boy or girl paradox', a.k.a. the Mrs Smith Problem.
Answer:
Step-by-step explanation:
given 
the factor (x - 3) can be cancelled from the numerator/ denominator leaving
Yes, it would only be irrational if the numbers had no end, (not repeating like .6666666…)
decimals that end, or repeat the same pattern are rational numbers.
Answer:
X= -3;
Y=78
Step-by-step explanation:
A: X+Y=75
B: 10X+Y=48
B-A: (10X+Y)-(X+Y)=48-75
10X+Y-X-Y= - 27
9X=-27
X= -3;
Now
A is : -3+Y=75
Y=75+3=78
