Acouple with a newborn baby is troubled that the child does not resemble either of them. suspecting that a mix-up occurred at the hospital, they check the blood type of the infant and find that it is type o. as the father is type a and the mother type b, they conclude that a mix-up must have occurred.

The result of this would greatly depend on the genotype of the parents. If either the father is homozygous Type A and the mother is homozygous Type B, then yes, a mix up has occurred because the probability of having an offspring with the blood type O would be zero. But if both of them are heterozygous, then having a child with type O will be possible with a 25% probability. 

We can use solar powered cars or ride bikes instead of cars that burn fossil fuels