Q) After adding a simple interest of $ 270 an investment becomes $1395. If the principal was invested at 6% p.a. simple interest, for how long was the principal invested.
A) 3 Years
B) 4 Years
C) 5 Years
D) 6 Years
E) 7 Years
Solution: As a Simple Interest problem, this question would make use of the formula,
SI = Principal * Rate * Time
Amount = SI + Principal
Plugging in values, we get,
$1395 = $ 270 + Principal
Principal = $1395 - $270 => $1125...
Which has the largest value?
a) 1/5 +1/5+ 1/5
b) 3/5*2/5 – 4/5*1/5
c) (½)^3 + (1/2)^2 + (1/2)^1
d) ½ +1/3 +1/6+1/8
e) 1/9 * (1/3+9/27+9/12)
To find the answer to the above question in the shortest time require remembering just two rules:
a) For Fraction a/b where a>b, then a/b is greater than b/a
b) Finding LCM is the easiest ways to simplify operation on fractions
Now let us try each answer choices...
Rhombus ABCD below is divided into three areas with AGH = 1/3rd Area of ABCD, ECF = 1/5th Area of ABCD. What is the ratio of Area (AGH) to CD, given that AC=12 and BD =16?
Q) What is the unit digit of (2) ^29 * (5) ^29 * (7) ^29?
To answer questions that involve multiplying large numbers and finding the unit digit, the solution is to find patterns within numbers. In this case, each number is raised to the 29th power and multiplied with each number. All numbers that are raised to a certain power follows a pattern. Let us look at each of them.
(2)^1 = 2
(2)^2 = 4
(2)^3 = 8
(2)^4 = 16
(2)^5 = 32
The power of 2 has unit digit in the following pattern (2,4,8,6)
Unit Digit of (2)^29 = 2 -> First...
Q) If a is an even integer, which of the following is definitely not an odd integer?
a) a*b, where b is odd
b) a/b, where b is an even number greater than 0
c) ab-1 where b is an even number greater than 3
d) 3(ab-2) where b is an even number
e) 5(a+b)where b is an odd number
Before we go into the question, remember the properties of odd and even number arithmetic operations:
Odd x Even = Even
Odd x Odd = Odd
Even x Even = Even
Odd + Even = Odd
Even – Odd = Odd
Odd + Odd = Even
Now let us look at the question: which of the following is definitely not an odd integer.
What is the ten’s digit of 7^195?
This question is based on the cyclicity concept in number theory.
Ten’s digit of powers of 7 follows a cyclic pattern as depicted:
7^1 = 07 7^5 = 16807
7^2 = 49 7^6 = 117649
7^3 = 34...
The sum of the first 6 terms of a geometric sequence is 9 times the sum of its first 3 terms. Find the common ratio.
Sum of n terms of a geometric series is given by a ( r^n – 1) / r – 1 where a, r and n are the first term, ratio and number of terms of the series respectively.
Peter runs 100 metres in 16 seconds, while Tracy takes 20 seconds to complete the same 100 metres. By what distance will Peter beat Tracy in a 100-meter race?
In questions pertaining to races, we have to compute the distances travelled or time taken by the competitors, to find the lags in positions.
Peter takes 16 seconds to run 100 metres, how much distance has Tracy run in that time?...
The L.C.M. of the two numbers is 35750 and their H.C.F. is 25. If, one of the numbers is 275, what is the other number?
Solution: There are two ways to solve this problem, one create two equations for L.C.M and H.C.F, and solve them to find the second number but a much simple solution would be to use an equation like:
A sample of 100 people was surveyed for the use of computers, cell phones and credit cards. 31 people had credit cards, 61 had computers and 28 had cell phones. If 11 people had none of the three and 32 people had more than one, how many had all the three?
Solution: This is a question based on Set Theory.
Total = 100
None = 11...
Car A, travelling at 60kmph leaves City X for City Y at 5pm. Car B leaves city X for City Y at 7pm and travels at 100 kmph. When will Car B overtake Car A?
A) 9:45 p.m
B) 9:55 p.m
C) 10:00 p.m
D) 10:05 p.m
E) 7:55 p.m
Solution: Questions related to overtaking in Time Speed and Distance are considered one of the most confusing ones in Quant. However, there...
John and Walter have their incomes in the ratio 7 : 5. The expenses of John, Walter and Nancy are in the ratio 9 : 7 : 4. If Nancy spends $2800 and Walter saves $1100, how much is John’s saving is?
Solution: There is some common element hidden in these type questions pertaining to Ratio and Proportion. If you can find that out, the rest of the solution is a cakewalk.
Let the expenses of John, Walter and Nancy be 9y, 7y and 4y...
A man working for 8 hours a day can complete a job in 12 days. He is paid a sum of $150 per day. Three women work as efficiently as two men, but are paid a sum of $10 per hour. A contractor needs to finish the job in 6 days. He has to decide between employing men or women. How much money will he save, if he employs women to do the job instead of men?
Terry has some oranges. Out of that, 4% were thrown away, 80% of the remaining oranges were sold and he is now left with 96 oranges. What was the initial number of oranges with him?
Solution: This is a Percentages question. Let us take variable X as the total number of initial oranges with Terry.
Oranges thrown away: 4%*X
Remaining oranges: 96%*X
Oranges sold: 80%*96%*X
Total oranges left: 96 oranges
The contents in beakers A and B are 90 litres of milk and 90 litres of water respectively. Now, 30 litres of milk is taken from A and put into beaker B. After thoroughly mixing, 12 litres of the mixture is taken from B and put into beaker A. Find the percentage of water in beaker A.
This is a question on Ratio and Proportion. The best way to solve these questions is to move step by step and analyse the mixture in terms...
During the past month, a disease control center tested X individuals for two viruses. If 1/3 of those tested had virus C and, of those with virus C, 1/5 also had virus D, how many individuals did not have both virus C and D?
E. 4 / 5
The number of individuals that had virus C is 1/3 of X, or X/3.
The number of individuals that also had virus D is 1/5 of the number that had virus C.
Thus (1/5)C= (1/5)(X/3) = X/15.
If X/15 of the X individuals have virus C and D, then X - (X/15) did not have both virus C and D.
Neither C or D: X - (X/...
How many inches are in a mile? (There are 5,280 feet in 1 mile and 12 inches in one foot)
We are given two conversion factors and are asked to start with 1 mile and convert it to inches. The first conversion relates miles to feet: 1 mile = 5,280 ft. Thus, the 1 mile we began with is equivalent to 5,280 feet. In order to convert from feet to inches, we must set up a conversion ratio.
Since 12 in = 1 ft, (12 in)/(1 ft) = 1.
Likewise, (1 ft)/(12 in) = 1 since 1ft = 12in. 5,280ft * (12in/1ft) = 5,280(12) in The equation below aligns the...
Which of the following must be even if A and B are integers and AB^2 + 3B is odd?
C. AB + 3
D. AB - 3
E. A + 3
The first step is to completely factor our given expression. In this case, since B is in each term, we can factor it out as follows: AB^2 + 3B = B (AB + 3).
Let's focus on this factored version of the expression.
Since AB + 3 must be odd, and we know that the sum of two numbers is odd only when one of the numbers is odd and the other is even, AB must be even (because 3 is odd).
The product of two integers is...