Answer: 130
Step-by-step explanation:
Let the 2 numbers be a and b.
a-b=100
The smaller number is decreased by 10.
b will become b-10.
The bigger number is increased by 20.
a will become a+20
The new difference is:
a + 20 - (b - 10)
= a + 20 - b + 10
= a - b + 30
But a-b=100
a - b + 30
100 + 30
130