Hello !
1. Calculate the rest
100% - 60% = 40%
=> 40% of police officers have ride-alongs
2. Make a table
total
number of policier 258 ? ??
frequency in % 60% 40% 100%
3. Calculate the total
3.1 Calculate the number of of the police officers have ride-alongs with teenagers who want to join the police force
? = 258 x 40 ÷ 60 = 172
3.2 Calculate the total
?? = 258 + 172 = 430
4. Conclusion
In total there are 430 police officers.
Have a good day !