Answer: 
Step-by-step explanation:
1. A number written in scientific notation has the following form:

Where is
is a number between 1 and 10 but not including 10, and b is an integer.
2. The negative exponent indicates the number of places the decimal point must be moved to the left to obtain the number as a decimal number.
3. Keeping this on mind, you can know that: if the exponent of a number written in scientific notation indicates that the decimal point must be moved 5 places to the left and another number written in scientific notation indicates that the decimal point must be moved 2 places to the left, then the first number is smaller than the second one.
4. Therefore, you can arrange the numbers given in the problem as following:

Answer:
32
Step-by-step explanation:
Suppose Alvin is x years old. Then Elga is x+15 years old.
x+x+15=49
2x=34
x=17
17+15=32
You could go down then up