ENNYSTON SCIENCE COMPETITION: 3RD ROUND - SENIOR 2

Simplify:  X/5 + 2X/3

• 13X/15

• 3X/15

• 8X/15

• 2X/5

The probability that Abu will fail Geography and Economics tests are I/3 and 1/2 respectively. If the two events are independent, find the probability that he will pass one of the subjects.    

• 1/3

• 1/4

• 4/5

• 1/2

If sinx = 3/5, what is the value of sinx + cosx?

• 7/5

• 5/7

• 4/5

• 3/5

Find the median of t+2, 2t -4, 3t+2 and 2t, assumming they are arranged in order of magnitude

• (5t + 2)/2

• (5t - 2)/2

• t - 2

• 2t - 4

A soldier hits a target three out of 4 times. If he has 3 shots, what is the probability that he will miss all?

• 1/3

• 1/9

• 1/4

• 1/64

A machine has a velocity ratio of 4. It requires 800 N to overcome a load of 1600 N. What is the efficiency of the machine?

                                     

• A.  2 %      

• B. 4 0 % 

• C. 50 %   

• D. 60%

The distance through which a screw moves along its head when the screw head is turned through one revolution is

                                 

• A.  Half a pitch

• B. the pitch 

• C. twice the pitch

• D. three times the pitch

The ratio of tensile stress to tensile strain is known as

                                      

• A.  Modulus of rigidity 

• B. modulus of elasticity

•   C. bulk modulus 

• D. Young’s modulus

An object weighs 220 N in water and 300 N in air. What is the upthrust exerted by the liquid on the object?

          

• A.  220 N   

• B. 80N

• C. 50N

•   D. 520N

  At what temperature is the Celsius and Fahrenheit temperature scale equal?

• -40

• 40

• -60

• 60