12. 6. Ferdy has to work 3 hours to make his homework done
while his classmate Bea needs 4 hours to do such homework.
Find the time required for them to finish a homework.
16. 8. An airplane flies at a height of 1500ft. When an anti-
aircraft gun is fired at it at an angle of 250
with a speed of
1000 ft/sec. Will the bullet be able to reach the airplane?
22. 11. A box is made from a 20 by 20 in cardboard. Find the
maximum volume of the box that can be made by cutting
equal square parts in each corner of the cardboard.
44. 22. A motorboat has an average speed of 20kph in still water. It can
travel upstream 5km against a river current in the same time it can
travel 7km with the river current. What is the speed of the current?
54. 27. Three fighter plane pilots were tasked to
rendezvous with a bomber squad bound for
Wake Island from the same airbase. Captain
Williams flies north at 200kph while Lt.
Winters flies at the same speed at N 50
E. Lt.
Peppers flies at the same speed at N 110
E.
What is the distance of two pilots from the
Captain after 3.5 hours of flying?
60. 30. Find the error in computing the volume
of a 15 cm high conical vessel if there is a
0.2% error in measuring the radius when
the height is always thrice the radius.
62. 31. Find the coefficient of friction between a 3.5kg
mass and a horizontal surface when a force of 9.5N is
needed to push it to a constant velocity.
64. 32. A particle’s position is defined by the equation
s=t3
-t2
where is the position in m and t is the time in
secs, find the velocity when the acceleration is 0.
74. 37. Bobby wanted to know the chances of him passing a 20 item
dichotomous examination. If the passing score is 80% of the total perfect
score. What is the chance for him to pass the exam using pure
guesswork?
76. 38. A cyclist travelled a certain distance at her usual speed. If her speed
had been 2 mph faster, she could have travelled the distance in hr less
time. If her speed had been 2 mph slower, she would have taken 2hr
longer. Find her usual speed.
80. 40. The hypotenuse of a right triangle is 25 ft. If one of the
acute angles increases at the rate 4 degrees per second,
how fast is the area increasing when the angle is 30 degrees?
88. 44. A thermometer reading 15 deg C is brought in a room whose
temperature is 26 deg C. 1 min and 30 secs later, the thermometer
reading is 16.5 deg C. How long does it take for the thermometer to
read 18 deg C?
90. 45. An unstretched spring is 10 ft. Long. A pull of 40 lb
stretches the spring by ½ ft. Find the work done in
stretching the spring from 10 ft to 14 ft.
92. 46. A conical tank is 12 ft across the top amd 8 ft deep. It contains
water to a depth of 6ft. Find the work done in pumping the water to a
point 2 ft above the top of the tank. Use sp. weight = 62.5 lb/ft3
94. 47. In a card game using a deck of cards without face cards, you will win
60 dollars if you picked up an even red card and lose 10 dollars if you
picked any other card. What is the expected winning for one picking of
a card?
96. 48. Peter, Paul, and Mary went to a ball sponsored by their friend Harry. Each table
serves 8 persons. The four of them decided to seat to observe the magnificent
ballet dance on the stage and decided to seat beside each other on a table with 4
other persons seated randomly. Find the number of ways they can seat together.
