Solve the following:
1. The difference in the ages of two persons is 20 years. 5 years ago, the older person was 5 times the ages of the younger one. Find their present age.
2. If a bicycle wheel has 60 spokes. Find the angle between a pair of two consecutive spokes.
3. Two fifth of a number is 100. Find the number.
4. If 150% of a number is 750. Find the value of 60% of the number.
5. The difference between two numbers is 7. The sum of the larger number and six times the smaller number is 77. Find the two numbers.
Answers:
1. 10 years and 30 years
2. 6°
3. 250
4. 300
5. 10, 17