Please help me with this

Suppose a man is heterozygous for heterochromia, an autosomal dominant disorder which causes two different‑colored eyes in an individual, produced 25‑offspring with his normal‑eyed wife. of their children, 15 were heterochromatic and 10 were‑normal. calculate the chi‑square value for this observation.

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

If you could answer these your a life saver