Skip to main content

Important Short Tips of Square Root ,Cube Root and Quant Quiz




















5. The least perfect square, which is divisible by each of 21, 36 and 66 is:
A. 213444
B. 214344
C. 214434      
D. 231444

6. How many two-digit numbers satisfy this property : The last digit (units digit) of the square of the two-digit number is 8 ?
A. 1
B. 2
C. 3
D. None of these

7.A group of students decided to collect as many paise from each member of group as is the number of members. If the total collection amounts to Rs. 59.29, the number of the member is the group is:
A. 57  
B. 67
C. 77  
D. 87

8. A group of students decided to collect as many paise from each member of group as is the number of members. If the total collection amounts to Rs. 98.01, the number of the member is the group is:
A. 101
B. 98
C. 99
D. 88

9.A man plants 49284 apple trees in his garden and arranges them so that there are as many rows as there are apples trees in each row. The number of rows is
A. 182
B. 202
C. 222
D. 122

10.If 0.13÷p^2=13, then p equals :
A. 0.01
B. 0.1
C. 10
D  100

ANSWER AND SOLUTION :




















6(D)Explanation :

A number ending with 8 can never become a perfect square
Let's examine this in detail
1 × 1 = 1
Hence, if the unit digit of a number is 1, unit digit of its square is 1
2 × 2 = 4
Hence, if the unit digit of a number is 2, unit digit of its square is 4
3 × 3 = 9
Hence, if the unit digit of a number is 3, unit digit of its square is 9
4 × 4 = 16
Hence, if the unit digit of a number is 4, unit digit of its square is 6
5 × 5 = 25
Hence, if the unit digit of a number is 5, unit digit of its square is 5
6 × 6 = 36
Hence, if the unit digit of a number is 6, unit digit of its square is 6
7 × 7 = 49
Hence, if the unit digit of a number is 7, unit digit of its square is 9
8 × 8 = 64
Hence, if the unit digit of a number is 8, unit digit of its square is 4
9 × 9 = 81
Hence, if the unit digit of a number is 9, unit digit of its square is 1
0 × 0 = 0
Hence, if the unit digit of a number is 0, unit digit of its square is 0



Comments

Post a Comment

Popular posts from this blog

Short Notes on Time and Distance

TIPS AND FORMULAS ON TIME AND DISTANCE: 1. Speed =   Distance/Time 2. Time =   Distance /Speed 3. Distance =  Speed x Time 4 . km/hr to m/s conversion: 1 kmph =   5/18 m/s 5.  m/s to km/hr conversion:   1 m/s =   18/5 m/s 6.  If the ratio of speeds of train A and B is a : b, then the ratio of time taken by them to cover the same distance =  b : a. 7.  If a man covers a certain distance at x km/hr and an equal distance at y km/hr. Then,the average speed during the whole journey is 2xy/(x + y) km/h 8 . The time taken by a train in passing a pole or standing man is the same as the time taken by the train to cover a distance equal to its own length. 9.  The time taken by a train of length 'L' metres in passing a stationary object of length 'B' metres is equal to the time taken by the train to cover a distance equal to  (L + B) m. 10.  If two trains are moving in the same directions at u m/s and v m...
Post a Comment
Read more

Study Notes of HCF and LCM and Aptitude Quiz

TIPS FOR SOLVING QUESTIONS RELATED TO HCF and LCM: Prime number :   A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. For example, 2, 3, 5, 7, 11, 13, etc. are prime numbers. Co-Prime Number:  Two numbers are said to be relatively prime, mutually prime, or co-prime to each other when they have no common factor or the only common positive factor of the two numbers is 1. In other words, two numbers are said to be co-primes if their H.C.F. is 1. Factors:  The numbers are said to be factors of a given number when they exactly divide that number. Thus, factors of 18 are 1, 2, 3, 6, 9 and 18. Common Factors:  A common factor of two or more numbers is a number which divides each of them exactly. Thus, each of the numbers - 2, 4 and 8 is a common factor of 8 and 24. Multiple:  When a number is exactly divisible by another number, then the former number is called the multiple of the...
Post a Comment
Read more

Quant Short Tricks on Multiplication

1.   Multiplication using multiples Assume that we should find out the result of 12 x 15.  12 x 15    ( Here we can write this 15 as 5 x 3) =  12 x 5 x 3 (now  12 x 5 becomes 60) =  60 x 3 ( For this you just calculate 3 x 6, that is 18 and add one Zero to it. that is 180) =  180 2.   Multiplication by distribution   Assume that we should find out the result of 12 x 17 12 x 17   ( Here we can divide this 17 as 10+7. Here, multiplying 12 with 17 is same as multiplying 12 with 10 and 7 separately and then adding the results) so, we can write it as = (12 x 10) + (12 x 7)  = 120 + 84 = 204  3.   Multiplication by "giving and taking" 12 x 47   ( Here its little difficult for us to calculate the multiplication of 12 and 47 mentally. so just check for the ROUNDED number nearer to 47. Yes it is 50. so..... = 12 x (50 - 3)...
Post a Comment
Read more