# Worked Examples

1. Observe the following chain of numbers carefully and answer the questions.
 5 3 7 7 3 4 2 6 3 7 2 7 1 3 7 7 3 7 3 4 3 2 3 7 6 1 3 7
1. How many 3s are followed by 7 but are not preceded by 1?
1. 2
2. 3
3. 4
4. 5
2. If all the 2s and 6s are dropped, which number is exactly between the 11th number from the left and the 15th number from the right?
1. 1
2. 3
3. 4
4. 7
3. How many pairs of consecutive numbers if added together amount to eight?
1. 2
2. 3
3. 4
4. 5
4. Beginning with the first number, make groups of four numbers and add the numbers in each group together. Which group has the highest sum?
1. 1st
2. 3rd
3. 4th
4. 7th
Analysis:
1. Mark all 3s in the given number chain, which are followed by 7 and not preceded by 1.
 5 3 7 7 3 4 2 6 3 7 2 7 1 3 7 7 3 7 3 4 3 2 3 7 6 1 3 7

There are four such 3s.

1. On dropping all 2s and 6s, the chain of number appears as under:
 5 3 7 7 3 4 3 7 7 1 3 7 7 3 7 3 4 3 3 7 1 3 7

3 and 7 are the 11th number from left and 15th number from right, respectively. 1 is the number between these two numbers.

1. Sum of each pair of consecutive numbers is furnished below:
 8 10 14 10 7 6 8 9 10 9 9 8 4 10 14 10 10 10 7 7 5 5 10 13 7 4 10

Three pairs of consecutive numbers add to 8.

1. If four numbers from the beginning are grouped together, we get 7 such groups. The sum of numbers in each group is as furnished below:
 22 15 19 18 17 15 17

Sum of numbers in the 1st group amounts to 22 and this is the highest.

1. Write the first 13 letters of English alphabet in the reverse order. Then write the remaining 13 letters in the reverse order.
1. How many letters are there between C and T?
1. 7
2. 16
3. 8
4. 15
2. Which is the letter exactly in the middle of the 15th letter from the right and the 18th letter from the left?
1. B
2. M
3. X
4. Y
3. Which is the letter to the right of the 20th letter from the right?
1. F
2. H
3. E
4. I
Analysis:

Write all the 26 letters of English alphabet as suggested in the problem.

 M L K J I H G F E D C B A Z Y X W V U T S R Q P O N
1. We observe that there are 8 letters between C and T.