To find the total amount of watermelon and strawberries used, we need to add the amount of watermelon used (1 1/4 pints) to the amount of strawberries used (5 1/8 pints). However, since the two amounts have different denominators, we need to convert them to a common denominator before adding.
1 1/4 = 5/4
5 1/8 = 41/8
To convert the fractions, we need to multiply the numerator and denominator of the first fraction by 8 (the denominator of the second fraction), and multiply the numerator and denominator of the second fraction by 4 (the denominator of the first fraction):
5/4 x 8/8 = 40/32
41/8 x 4/4 = 164/32
Now we can add the two fractions:
5/4 + 41/8 = 40/32 + 164/32 = 204/32
We can simplify this fraction by dividing both the numerator and denominator by their greatest common factor (GCF), which is 4:
204/32 = 51/8
Therefore, Ali used a total of 51/8 pints of watermelon and strawberries in the fruit salad.