Skip to main content

Aptitude Day 269


Problems on Time and Distance:

1. A person travels from P to Q at a speed of 50 km/hr and returns by increasing his speed by 20%. What’s his average speed for both the trips?

Solution:
                  120% of 50 = 120/100*[50] = 60 km/hr.

                  Average speed = 2*50*60/[50+60] 
                                          = 6000/110 
                                          = 54.55 km/hr.

2. A car travels the 1st one-third of a certain distance with a speed of 20 km/hr, the 2nd one-third with a speed of 10 km/hr, and the last one-third distance with a speed of 30 km/hr. The average speed of the car of the whole journey.

Solution:
                  Let the whole distance and speed be x and y respectively.
                  (x/3)/20 + (x/3)/10 + (x/3)/30 = x/y

                  By solving the above equation, we get
                  y = 180/11 
                     = 16(4/11) km/hr.



Comments

Post a Comment

Popular posts from this blog

Aptitude Day 332

Answers of Day 331: 1. 450%.                                     2. 10.   Problems on Percentage: 1. 0.001 is what percent of 0.01? Solution:                   0.001/0.01 * 100 = 1/10* 100                                               = 10%. 2. A fruit seller had some apples. He sells 20% apples and still has 500 apples. Originally, he had: Solution:                (100-20)% of x = 500                80/100*x = 500                x = 625.
Post a Comment
Read more

Vocabulary Day 21

Stammer Thesaurus: Verb : stutter in speech, speak haltingly, speech defect           halt, hesitate, pause, stop, sputter... Antonyms : say quickly, pronounce, enunciate... Example sentences: ·          He was stammering when the teacher caught him red-handed. ·          One should avoid the stammering while delivering a speech. 
Post a Comment
Read more