please help me understand with some short written explanations, questions 20 AND 24 ONLY, thank you

20. In the ideal estate plan, what amount would be transferred to a testamentary bypass trust? 21. List the various forms of grantor retained income trusts (GRITs). 22. What is the primary reason to use a GRAT for estate planning purposes? 23. List the primary difference between a GRAT and a GRUT. 24. How is a GRAT more effective in reducing the grantor's gross estate than a GRUT? 25. Discuss the consequences of a grantor dying during the term of a TPPT. 26. What is a dynasty trust and what is its primary purpose? 27. Who is subject to the income tax on the income of a grantor trust? 28. What is the primary purpose of using a 2503(b) or 2503(c) trust? 29. List the requirements of a 2503(b) trust. 30. Describe a Totten Trust and its benefits. 31. What are the three types of special needs trusts? 32. Describe a third party special needs trust. 33. What are some of the requirement for a special needs trust under 42 U.S.C. Sec. 1396p(d)(4)(A) ? 34. Why are IRAs of interest in estate planning? 35. What is the purpose of a trusteed IRA? 36. Does the IRS require the trustee of a see-through trust to provide the complete trust instrument to the custodian? 37. Describe at least two methods by which an irrevocable trust may be modified