Answer:
166
Step-by-step explanation:
Do the parathisis first
(2x12)=24
(5x6)=30
Then do
220-24-30=166
Let Mary's age be x.
Paul is three times as old as Mary, so Paul's age would be 3x.
Peter is four times as old as Mary, so Peter's age would be 4x.
The sum of their ages is 64
⇒ Paul's age+ Peter's age+ Mary's age= 64
⇒ 3x+ 4x+ x= 64
⇒ 8x= 64
⇒ x= 64/8
⇒ x= 8
Paul's age is: 3x= 3*8= 24
Peter's age is: 4x= 4*8= 32
Final answer: Paul is 24 years old.
Peter is 32 years old.
Mary is 8 years old.
Hope this helps~
Recall your d = rt, distance = rate * time
now, if say, by the time they meet, Mr Cunningham has travelled "d" miles, that means Mrs Cunningham must also had travelled "d" miles as well.
However, he left 3 hours earlier, so by the time he travelled "d" miles, and took say "t" hours, for her it took 3 hour less, because she started driving 3 hours later, so, she's been on the road 3 hours less than Mr Cunningham, so by the time they meet, Mrs Cunningham has travelled then "t - 3" hours.