Answer:
Total amount donted by Danny class is 1.21d .
Option (a) is correct .
Explanation:
As given
Ron’s class donated d dollars to a local charity.
Danny’s class donated 21% more than Ron’s class.
21% is written in the decimal form .

= 0.21
Danny class donted more than Ron class = 0.21 × Ron class donated
= 0.21d
Total amount Danny class donated = Ron class donated + Danny class donted more than Ron class
= d + 0.21d
= 1.21d
Therefore total amount donted by Danny class is 1.21d .
Option (a) is correct .