I need help with this math problem on percents

What is the compound interest in a three-year, $100,000 loan at a 10 percent annual interest rate a) 10.00 b) 21.00 c) 33.10 d) 46.41

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is