Can someone help me with this question?!

Average atomic mass  = 32 amu

Explanation:

Given data:

Abundance of X-30.00 amu = 30%

Abundance of X-32.00 amu = 50%

Abundance of X-35.00 amu = 20%

Average atomic mass = ?

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  +(abundance of 3rd isotope × its atomic mass)  / 100

Average atomic mass  = (30×30)+(50×32)+(20×35) /100

Average atomic mass =  900 + 1600 +700 / 100

Average atomic mass = 3200 / 100

Average atomic mass  = 32 amu.