1) Mean= Sum of total Observation/ Total no.of observation
Mean= 42/6=7
option (b) 7
2)To calculate Median first arrange the numbers in a numerically ascending order.
Since, there are even no.of total Observation median will be the mean of two middlemost terms.
3,6,7,9,9,10
Middle terms are 7 and 9
Median= 7+9/2= 8
option(c) 8