Wale is twice as old as Bola. If Wale is 24 years, how old is Bola?

Express a speed of 20 m/s in km/hr.

160 out of 800 candidates from a state who took the Secondary Entrance Exam were called for interview.

What percentage of the candidate were not called for the interview?

An elastic string is stretched from 45 cm to 60 cm.
Find the percentage increase in length.

An athlete placed on special diet was able to reduce her weight from 68 kg to 51 kg.
Find her percentage reduction in weight.

Find the distance round a square field whose area is 400 m².

The diagram below shows the number of students taking at least one of Mathematics, English or Biology.


How many students offer English only?

The following marks were scored in a Chemistry test by 10 students:
62,  84,  12,  25,  60,  72,  80,  0,  50  and 55.

What is the median score?

What is the missing number in the following addition:

37.4  +  ................  +  15.7  =  55.3

Nnamdi defrosts his refrigerator regularly every 4 weeks 4 days.

How many weeks and days have passed after he had defrosted it ten times?

Find the cost of 12 dozens of pencils at 8 kobo each.

Correct 0.006678 to 3 significant figures

Evaluate 

721   x   20

A football team loses three of their five penalty kicks.

What percentage of the kicks was successful?

How many complete pieces of twine each of length 40 cm can be cut from a coil containing 200 cm?

If today is Friday, what day of the week will it be in 1005 days' time?

Express 2.45 in fraction.

If 5 men dug a well in 14 days, how many days will it take 7 men?

All of these are prime numbers EXCEPT

Find the sum of 

0.0017,  1.45  and   0.001