Refresher - MATHEMATICS Quiz 2
PROBLEM 1:
Two thirds of people in a party are lawyers, whose average I.Q. is 120.
The rest are engineers whose I.Q. is 180. What is the average I.Q. of all
persons in the room?
Solution:
2 1
n(x) = x (120) + x (180)
3 3
n = 140 average I.Q.
, Refresher - MATHEMATICS Quiz 2
PROBLEM 2:
A commercial fishing boat uses sonar equipment to detect a school of fish 2 miles east of
the boat and traveling in the direction of N 51˚ W at a rate of 8 mi/hr.
➀ If the boat travels at 20 mi/hr, approximate to the nearest 0.1˚ direction it should head to
intercept the school of fish.
➁ Find to the nearest minute the time will it take the boat to reach the fish
Solution:
N
8t
126.4˚
20t
51˚
=14.6˚ 39˚
Boat 2 miles
8t 20t
=
Sin θ Sin 39˚
θ = 14.6˚
90 - 14.6 = 75.4˚
Headingofofboat
Heading boatto to intercept
intercept the the school
school first =first = N. 75.4˚
N. 75.4˚ E E
Time will it take the boat to reach the fish
20t 2
=
Sin 39˚ Sin 126.4˚
t = 0.08 hrs = 5 min
PROBLEM 1:
Two thirds of people in a party are lawyers, whose average I.Q. is 120.
The rest are engineers whose I.Q. is 180. What is the average I.Q. of all
persons in the room?
Solution:
2 1
n(x) = x (120) + x (180)
3 3
n = 140 average I.Q.
, Refresher - MATHEMATICS Quiz 2
PROBLEM 2:
A commercial fishing boat uses sonar equipment to detect a school of fish 2 miles east of
the boat and traveling in the direction of N 51˚ W at a rate of 8 mi/hr.
➀ If the boat travels at 20 mi/hr, approximate to the nearest 0.1˚ direction it should head to
intercept the school of fish.
➁ Find to the nearest minute the time will it take the boat to reach the fish
Solution:
N
8t
126.4˚
20t
51˚
=14.6˚ 39˚
Boat 2 miles
8t 20t
=
Sin θ Sin 39˚
θ = 14.6˚
90 - 14.6 = 75.4˚
Headingofofboat
Heading boatto to intercept
intercept the the school
school first =first = N. 75.4˚
N. 75.4˚ E E
Time will it take the boat to reach the fish
20t 2
=
Sin 39˚ Sin 126.4˚
t = 0.08 hrs = 5 min
