Find the median from the following data.
| Age in years | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 | 80-90 |
| No. of patients | 12 | 16 | 30 | 20 | 17 | 38 | 15 |
The volume and height of a cylinder are 8470 cm3 and 2.2 cm, respectively. Find the radius (in cm) of the cylinder. (Use pi = \( \frac{22}{7} \))
A group of numbers and symbols is coded using letter codes as per the codes given below and the conditions that follow. Study the given codes and conditions and answer the question that follows.
Note: If none of the conditions apply, then codes for the respective number/symbol are to be followed directly as given in the table.
| Number/symbol | 6 | ÷ | 7 | % | @ | + | 8 | 4 | - | 2 | # | 3 | 9 | & |
| Code | P | E | S | H | W | Q | G | T | I | M | Z | A | V | R |
Conditions:
If the first element is a prime number and the last element is an even number, then the codes for these two (first and last elements) are to be interchanged.
If the third element is a symbol, then it is to be coded as alpha.
If both the second and the fourth elements are perfect numbers, then the fourth number is to be coded as the code for the second element. What will be the code for the following group?
3 / 7 @ 4