How many possible birth orders with respect to gender are possible in a family with four children? (for example, bbgg & ggbg are different orders) how many possible birth orders for a family with 4 children are there ?

The first week samantha learned to read braille, she could read 10 words per minute. in the second week she increased her speed by 20%. in the third week she increased her speed again by another 25%. how many words could she read per minute by the third week? hurry and tell me!