Number System
- The last digit of the number obtained by multiplying the numbers 41 x 42 x 43 x 44 x 45 x 46 x 47 x 48 x 49 will be ?
-
View Hint View Answer Discuss in Forum
Last digit will be multiplication of 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9.
It includes 5 & 2.Correct Option: A
Last digit will be multiplication of 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9.
It includes 5 & 2.
So, 5 x 2=10,
0 will be the last digit.
- The sum of the digits of a two digit number is 10, when the number is reversed, the number increases by 72.Find the number.
-
View Hint View Answer Discuss in Forum
Go through the options.
Correct Option: C
By checking options
91-19=72
Or
Let the number be xy
So 10x + y = 10 ..... (i)
When the number is reversed the new number is yx
So (10y + 10 ) - ( 10x +y ) = 72 ....(ii)
From Eqs. (i) & (ii)
x = 1 and y =9
∴number = 19
- Find the product of place value and face value of 5 in 65231
-
View Hint View Answer Discuss in Forum
Place value of 5 in 65231 = 5 x 1000
Face value = 5Correct Option: B
Place value of 5 in 65231 = 5 x 1000
= 5000
Face value = 5
required product = 5000 x 5 = 25000
- The units digit in the product ( 784 x 618 x 917 x 463 ) is
-
View Hint View Answer Discuss in Forum
Units digit in the given product = Units digit of 4 x 8 x 7 x 3
Correct Option: A
Units digit in the given product = Units digit of 4 x 8 x 7 x 3
= Units digit of 672
= 2
- If 1x5x01 is divisible by 11, then the value of x is
-
View Hint View Answer Discuss in Forum
N/A
Correct Option: C
When a number is divisible by 11, then sum of numbers at even place - sum of numbers at odd place = 0 or divisible by 11.
( x + x + 1 ) - ( 1+ 5 + 0 ) = 11
⇒ 2x - 5 = 11
∴ x = 8