Well since the chance of getting heads is 50% and half of 8 is 4 I would say you have atleast a 40-45% chance of getting 3 heads.
I suppose that the correct answer could be
2y=7
X^2+24^2 = (x+ 16)^2
X^2+576 = (x + 16)^2
I just use guess and check
10^2+576=(10+16)^2
100+576=26^2
676=676
So x=10
Scientific notion always has a number times 10 to the power of something.
So

Now if you had to round then it would become
پکانے سہ ہر ی دہ ۱۰ش۹ ی گیت تھا قیاتتعر ریگستان گیا