NPV Profile Question difference, between, discount

nixie24

Project 1
CF
0 100
1 36
2 36
3 36
4 36
NPV 14.12 IRR 16.37
Project 2
CF
0 100
1 0
2 0
3 0
4 175
NPV 19.53 IRR 15.02
Require return 10%
How do you find the discount rate that will cause the same NPV? I know you need to add the difference in cash flows and create a new project But from there I am kinda lost…can somehelp help me out?
Answer is a rate between 10 and 15.02 %