How many numbers of five digits can be formed by using 1, 2, 3, 4, 5, if 4 is necessarily taken at hundred's
place and 2 is not allowed at unit's place. Repetition of numbers is not allowed.
4 is necessarily taken at hundred's place and 2 is not allowed at unit's place,
hence number of methods = 1*3*3*2*1 = 18
You can also check the answer by making different numbers under given conditions.
Rules for making these codes are
1. Capital letter should be capital.
2. Small letter should be small.
3. Letters are changed according to the sequence given below
a b c d e f g h i j k l m n o p q r s t u v w x y z
z y x w v u t s r q p o n m l k j i h g f e d c b a
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Z Y X W V U T S R Q P O N M L K J I H G F E D C B A
In an examination of 500 marks (5 subjects & 100 marks for each subject), Amit got first class
certificate with 67.8 % . If he got perfect square marks in all the subjects, then what are
the number of possible methods for taking these marks in all the subjects.
The possible combination of marks is 49, 64, 64, 81, 81 Total number of methods for providing
81 marks for any 2 subjects out of 5 subjects is 10, then number of methods for providing
64 marks for any 2 subjects out of remaining 3 subjects is 3, then 49 marks is provided
for the last subject. Hence total number of methods are 10*3*1 = 30
On taking factors of all the numbers of 4956, we get 2*2, 3*3, 5, 2*3
Total numbers = 7
Similarly in 3878, we get 3, 2*2*2, 7, 2*2*2
Total numbers = 8
Similarly for others
If in a coded manner prices of following fruits are as given in the list below
Fruit Price (per Kg)
ORANGE 10
BANANA 5.50
MANGO 10
GRAPE 9.40
Then the price (per Kg) of GUAVA is
Sum of positional values of all the letters of the word ORANGE is 15+18+1+14+7+5 = 60
Average per letter is 60/6 = 10, hence the price
Similarly for others,
A sector of circle of radius equal to one fourth of the diagonal of square is cut from the square
taking one corner of the square as centre. If side of the square is 4 cm. then area of the remaining part is
Diagonal of the square = 4√2 cm.
Hence radius of the circle = 4√2/4 cm. = √2 cm.
Area of the sector of circle = 1/4 (π* radius2)
= 1/4 (π* (√2)2 )
= π/2
Area of the square = 4*4 = =16 cm.2
Hence area of remaining part = 16- (π/2) cm.2
On arranging all the letters of the words IS, AM, ARE, WAS, WERE in increasing order we get
AA, AE, EEI, MRR, SSWW as the code for corresponding words. On taking their positional equivalent, we get
IS = AA = 1+1 = 2
AM = AE = 1+5 = 6
Similarly for others