Question
The distance of the School and house of Suresh is 80 km.
One day he was late by 1 hour than the normal time to leave for the college, so he increased his speed by 4km/h and thus he reached to college at the normal time. What is the changed speed of Suresh?Solution
ATQ, we can say that Let the actual speed of Suresh be x km/hr According to the question 80/x– 80/(x + 4) = 1 80 [(x + 4 – x) / (x2 + 4x)] = 1 320 = x2 + 4x x2 + 4x – 320 = 0 x2 + 20x – 16x – 320 = 0 x (x + 20) – 16 (x + 20) = 0 (x + 20) (x – 16) = 0 Taking, (x + 20) = 0 x = -20 (not possible) Taking, (x – 16) = 0 x = 16 Speed of Suresh = 16 km/hr ∴ Changed speed of Suresh = 16 + 4 = 20 km/hr
Arjun sets aside 20% of his monthly earnings. If his monthly expenses rise by 45% while his monthly savings remain constant, determine the % increase in...
A man spends 20% and 12% of his monthly salary on rent and transportation, respectively. Out of the remaining money, he spends 30% on food and 45% on en...
Neha goes to a bookstore with a certain amount of money. She can buy 60 notebooks or 20 novels with the money she has. However, she saves 15% of the amo...
A candidate who gets 25% marks fails by 12 marks but another candidate who gets 45% marks gets 10% more than the passing marks. Find the maximum marks.
In a stock of electronics (laptops + mobiles), if 25% of mobiles were laptops, then the number of laptops would have been 150% more than that of mobiles...
Income of A is twice the income of B. B and A spend 20% and 30% respectively of their incomes. Find the savings of A, if B saves Rs. 18550 in a month.
- In 2020, the number of students in a school was 1,200. It rose by 15% in 2021, then fell by 10% in 2022, and finally rose by 25% in 2023. What was the tota...
- In an election, 7% of the total voters didn’t participate. Out of the remaining, one candidate received 49% of the total votes and won the election by 12...
- Price of rice is increased by 25%. Find the percentage by which consumption must be decreased so that expenditure on rice remains unchanged.
The income of ‘A’ increases by 20% every year. If his income 2 years hence from now will be Rs. 86400, then find his income a year before from now.<...
Relevant for Exams:
