Aptitude Made Easy: The Complete Guide to Success

In this question, we calculate the principal amount based on the total amount accrued in simple interest over two different time periods. The problem tests your understanding of simple interest and how to deduce the principal from given data.

This practical problem-solving scenario is helpful for understanding financial mathematics and real-world applications.

In this lesson, we explore how to calculate the principal amount (the initial investment or loan) when you know the total amount after interest and the interest itself. The formula used is:

$$\text{Principal}=\text{Total Amount}-\text{Interest}$$

This video provides a step-by-step guide on how to rearrange the formula and solve for the principal in simple interest problems.

This lesson shows how changing the interest rate affects both the principal amount and the time required to earn a certain amount of interest. You will learn how to adjust calculations when the interest rate changes.

To find the rate of interest, we use the simple interest formula:

SI=P×R×T100SI = frac{P times R times T}{100}SI=100P×R×T​

Here, SI is 1 paisa (or 0.01 rupee), P is 1 rupee, and T is 1 month (or 1/12 years). We need to find R (rate per annum). Substituting the values, we can calculate R and determine the correct interest rate.

A can complete a task in 4 hours, B and C together can finish it in 3 hours, and A and C together can finish it in 2 hours. How long will B take to complete the task by himself?

Simple Description:

This question involves finding the individual time taken by B to complete the task. We use the concept of work rates:

• A’s rate of work is 1/4 (since A completes the work in 4 hours).
• B and C together can complete it in 3 hours (rate 1/3).
• A and C together can complete it in 2 hours (rate 1/2).

By subtracting the rates, we can calculate B's rate and then find how long B will take to finish the work alone.

This question asks how long A will take to complete the work alone, given that A and B together can finish it in 12 days and B alone can finish it in 30 days. By finding the work rate of A, we can determine A's time.

This question asks how many days B will take to complete the work alone, given the combined work rates of A & B, A & C, and B & C. Using these rates, we can calculate the time B will take on his own.

This question asks how many days C will take to complete the work alone, given the combined work rates of A & B, B & C, and C & A. By using these rates, we can calculate the time C will take.

A train, 150 m long, takes 30 seconds to cross a bridge 500 m long. How much time will the train take to cross a platform 370 m long ?

a)      36 secs

b)      30 secs

c)       24 secs

d)      18 secs

A train 200 m long running at 36 kmph takes 55 seconds to cross a bridge. The length of the bridge is ?

If a man running at 15 kmph crosses a bridge in 5 minutes, the length of the bridge is ?

A train, 200 metre long, is running at a speed of 54 km/hr. The time in seconds that will be taken by train to cross a 175 metre long bridge is ?

The ages of X and Y are in the proportion of 6:5 and total of their ages is 44 years. The proportion of their ages after 8 years will be ?

If Raj was one-third as old as Rahim 5 years back and Raj is 17 years old now, How old is Rahim now ?

The sum of the ages of father and his son is 44 years. If 6 years after the father will be 3 times as old as his son, what are their present ages ?

Six years ago the ratio of the ages of Preeti and Ruchi was 6: 5. After four years the ratio of their ages will be 11: 10. What is Ruchi's present age ?

The product of the ages of Shyam and Ram is 240. If double the age of Ram is more than Shyam's age by 4 years, what is Ram's present age ?

A man walking at the rate of 5 km/hr. crosses a bridge in 15 minutes. The length of the bridge (in metres) is ?

A man travelled a certain distance by train at the rate of 25 kmph. and walked back at the rate of 4 kmph. If the whole journey took 5 hours 48 minutes, the distance was ?

A man riding his bicycle covers 150 metres in 25 seconds. What is his speed in km per hour ?

a)      25

b)      21.6

c)       23

d)      20

A journey takes 4 hours 30 minutes at a speed of 60 km/hr. If the speed is 15 m/s, then the journey will take ?

A and B are 20 km apart. A can walk at an average speed of 4 km/ hour and B at 6 km/hr. If they start walking towards each other at 7 A. m., when they will meet ?

The prices of a refrigerator and a television set are in the ratio 5 : 3. If the refrigerator costs 5500 more than the television set, then the price of the refrigerator is ?

An article is sold at 5% profit. The ratio of selling price and cost price will be ?

To gain 10% on selling sample milk at the cost price of pure milk, the quantity of water to be mixed with 50 kg. of pure milk is ?

On selling an article for 170, a shopkeeper loses 15%. In order to gain 20%, he must sell that article at ?

Arvind purchased a wrist watch with 30% discount on the labelled price. He sold it with 40% profit on the price he bought. What was his percent loss on the labelled price ?

Two pipes A and B can fill a tank in 20 minutes and 30 minutes respectively. If both pipes are opened together, the time taken to fill the tank is ?

Two pipes A and B can fill a tank in 15 minutes and 20 minutes respectively. Both the pipes are opened together but after 4 minutes, pipe A is turned off. What is the total time required to fill the tank ?

A cistern is normally filled in 8 hours but takes two hours longer to fill because of a leak in its bottom. If the cistern is full, the leak will empty it in ?

A person can row a distance of one km upstream in ten minutes and downstream in four minutes. What is the speed of the stream ?

A boat sails 15 km of a river towards upstream in 5 hours. How long will it take to cover the same distance downstream, if the speed of current is one-fourth the speed of the boat in still water ?

A man can row 8 kmh in still water. If the river is running at 2 kmh, it takes 4 hrs more upstream than to go downstream for the same distance. Then the distance is given by ?

Which word does NOT belong with the others?

a)      parsley

b)      basil

c)       dill

d)      mayonnaise

Which word does NOT belong with the others?

a)      book

b)      index

c)       glossary

d)      chapter

Introducing a boy, a girl said, "He is the son of the daughter of the father of my uncle." How is the boy related to the girl?

a)      Brother

b)      Nephew

c)       Uncle

d)      Son-in-law

If A + B means A is the sister of B; A x B means A is the wife of B, A % B means A is the father of B and A - B means A is the brother of B. Which of the following means T is the daughter of P?

a)      P x Q % R + S - T

b)      P x Q % R - T + S

c)       P x Q % R + T - S

d)      P x Q % R + S + T

Find out from amongst the four alternatives as to how the pattern would appear when the transparent sheet is folded at the dotted line.

     (X)                     (1)                 (2)                 (3)                 (4)

Choose the set of figures which follows the given rule.

Rule: Any figure can be traced by a single unbroken line without retracting.

Select the figure which satisfies the same conditions of placement of the dots as in Figure-X.

Group the given figures into three classes using each figure only once.

It has been established that

The Proper sequence should be:

a)      SRPQ

b)      QPRS

c)       QPSR

d)      RQPS