Find the arithmetic mean of the following data (correct to two places of decimals).
Class interval: 5-15, 15-25, 25-35, 35-45, 45-55, 55-65
Frequency: 12, 18, 8, 14, 16, 8
Which of the following letter-clusters should replace # and % so that the pattern and relationship followed between the letter-cluster pair on the left side of :: is the same as that on the right side of ::?
# : RXT :: FLH : %
Two taps can fill a cistern in 2 hours and 45 hours respectively. A third tap can empty it in 45 hours. How long (in hours) will it take to fill the empty cistern, if all of them are opened together?
Samples of four metals A, B, C and D were taken and added to a solution individually. The results obtained have been listed as follows.
A can displace B from its solution
B can displace D from its solution
C can displace D from its solution
C can displace A from its solution
Which is the most reactive metal?