If statement with a whole list of things inside it

Im struggling on a formula:

=IF(B5=75,IF(B4<2.5, ROUND(SUM(B3/B2)+1,0),0,0),)

if b7 equals 75, then if B4 is less than 2.5, divide b3 by b2 and round it up to the next whole number then add 1, or if b4 if larger than 2.5 return 0 or is b5 is not "75" then return 0

so a correct result would be:

B4=2.4
B5=75

B3(2.0) devided by B2(.04) rounded up to nearest whole number =6 plus 1 =7

Thank you for your time. Looking forward to the help, its driving me insane!