Three siblings are born 5 years apart, each. If the eldest child is 20 years old now, what's the total of the ages of the three siblings 10 years from now? Think carefully first, then make a decision:
Ten years from now, the elder child will be 20 + 10 = 30 years old. If the elder child is 20 years old now, the second born is 20 - 5 = 15 years old, 5 years younger than the firstborn. The second - born will be 15 + 10 = 25 years old ten years from now. The total age of the first and second - born 10 years from now will be 25 + 30 = 55. The third - born who is five years younger than the second born is 15 - 5 = 10 years old. The third sibling's age ten years from now will be 10 + 10 = 20 years old. The total age of the three siblings ten years from now will be 55 + 20 = 75 years. So, the answer is 75.