Tips and Tricks of The Day


Record Limit : 

    2019-03-19 11:21:57.0
Ex: The income of A is 150% of the income of B and the income of C is 120% of the income of A. If the total income of A, B and C together is Rs 86,000, what is C’s income?
A. Rs 30,000
B. Rs 32,000
C. Rs 20,000
D. Rs 36,000
Trick:
Ratio of income of
A:B:C = 15:10:18
so, 15x + 10x + 18x = 86000
x = 2000
C’s income = 18 × 2000 = 36000
    2019-03-18 11:00:50.0
Ex: If the total cost of 73 articles having total cost is Rs. 5110 and the total selling price of 89 such articles is Rs. 5607, then in the transaction, there will be -
(A) Loss of 15%
(B) Gain of 10%
(C) Loss of 10%
(D) Gain of 15%
Trick:
C.P. of 73 articles= 5110
C.P. of 89 articles= 5110/73 * 89 = 6230
Total S.P. of 89 articles = 5607
Loss = 6230 – 5607 = 623
Loss = 623/6230 * 100 = 10%
    2019-03-15 12:30:49.0
Ex: The cost of 4 rings and 2 bangles is Rs. 57200. What is the cost of 6 rings and 3 bangles ?
(A) Rs. 95, 340 
(B) Rs. 85, 800 
(C) Rs. 76, 600 
(D) Can not be determined 
Trick:
4R+2B = 57200, 2(2R+1B) = 57200
2R+1B = 28600
The cost of 6 Rings and 3 Bangles
3 (2R+1B) = 28600×3, 6R+3B = Rs. 85800
    2019-03-14 11:52:29.0
Ex: The sum of circumference of a circle and perimeter of square is 380 cm. The diameter of circle is 70 cm. What is the sum of area of circle and square?
A. 5450 sq. cm. 
B. 5220 sq. cm. 
C. 5080 sq. cm. 
D. Can't be determined 
Trick:
2πr + 4a = 380
2 × 22/7 × 35 + 4a = 380
4a = 160
a = 40 cm
Sum = 22/7 × 35 × 35 + (40)2 = 3850 + 1600
= 5450 cm.2
    2019-03-13 11:56:17.0
Ex: A bag contains 3 white balls and 2 black balls. Another bag contains 2 white and 4 black balls. A bag and a ball are picked random. The probability that the ball will be white is:
(A) 4/15       
(B) 3/5         
(C) 7/15          
(D) 9/16
Trick:
The probability of selecting one bag =1/2
Now, probability of getting a white ball from bag A:
= 1/2×3/5 = 3/10 
and probability of getting a white ball from bag B:
= 1/2×2/6 = 1/6 
Hence, Probability that white ball is drawn either first or second bag:
= 3/10+1/6 = 7/15
    2019-03-12 12:18:34.0
Ex: The average of four consecutive odd numbers is 36. What is the smallest of these numbers? 
(A) 31
(B) 35 
(C) 43
(D) 33
Correct answer: A
Trick:
Let the numbers be x, x + 2, x + 4, x + 6
x + x + 2 + x + 4 + x + 6 = 144
4x = 144 – 12 
4x = 132 
x = 33
Smallest number = 33 
    2019-03-11 11:39:55.0
Ex: Naimish present age, is three times his daughter's present age and nine-thirteenth of his mother's present age. The sum of the present age of all of them is 125 years. What is the difference between the Naimish's daughter present age and Naimish's mother present age?
A. 25 
B. 32 
C. 50 
D. 45
Correct answer: C
Trick:
D : N = 1 : 3, N : M = 9 : 13
D : N : M = 9 : 27 : 39 = 3 : 9 : 13
3x + 9x + 13x = 125, 25x = 125, x = 5
13x - 3x = 10x = 50
    2019-03-08 11:41:22.0
Ex: Some equations are solved on the basis of a certain system. Find out the correct answer for the unsolved equation on that basis.
                              If 3+8 = 24, 15+5 = 75 and 7+3 = 21, what is 6+9 = ?
A. 40
B. 42
C. 54
D. 36
Correct answer: C
Trick:
3 + 8⇒ 3×8 = 24
15 + 5⇒ 15×5 = 75
7 + 3⇒7×3 = 21
6 + 9 ⇒ 6×9 = 54
    2019-03-07 12:33:36.0
Ex: Tap A and tap B can fill a tank in 12 minutes and 15 minutes respectively and tap C can empty it in 6 minutes. Taps A and B are opened first and after 5 minutes, tap C is also opened. The tank is emptied in -
(A) 30 minutes
(B) 33 minutes
(C) 45 minutes
(D) 50 minutes
Correct answer: C
Trick:
A.......12 minutes [5 units per minute]
B........15 minutes [4 units per minute]
C........6 minutes [10 units per minute]
[L.C.M. of 12, 15 and 6]
According to the question
5 × (5 + 4) = (– 1) × n
45 = – n 
n = 45 
    2019-03-06 10:44:32.0
Ex: Select the correct combination of mathematical signs to replace * signs and to balance the, given equation. 
                                                   6 * 2 * 1 * 9 * 2 * 5 
A. = x ÷ − +
B. − + = − + 
C. x + = x −
D. = − + + x 
Correct answer: C
Trick:
6 x 2 + 1 = 9 x 2 – 5 
12 + 1 = 18 – 5 
13 = 13