 ### SPEED TIME, DISTANCE

A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour? A. 3.6 B. 7.2 C. 8.4 D. 10 Answer: Option B Explanation: Speed = 600/ 5… ### PROBLEMS ON AGES

Father is aged three times more than his son Ali’s. After 8 years, he would be two and a half times of Ali’s age. After further 8 years, how many times would he be of… ### IMPORTANT FORMULAS

Speed, Time and Distance: Speed = (Distance/ Time), Time= (Distance/Speed), Distance = (Speed x Time). Time Speed km/hr to m/sec conversion: x km/hr = x x 5/18 m/sec. m/sec to km/hr conversion: x m/sec =… ### AVERAGE

Important formulas of average Average: Average = (Sum of observations/ Number of observations) Average Speed: Suppose a man covers a certain distance at x kmph and an equal distance at y kmph. Then, the average… ### PROFITS AND LOSS

IMPORTANT FACTS Cost Price: The price, at which an article is purchased, is called its cost price, abbreviated as C.P. Selling Price: The price, at which an article is sold, is called its selling prices,… ### PERCENTAGE

Concept of Percentage: By a certain percent, we mean that many hundredths. Thus, x percent means x hundredths, written as x%. To express x% as a fraction: We have, x% = x/100 Thus, 20% =20/100… ### RATIO AND PROPORTION

Ratio: The ratio of two quantities a and b in the same units, is the fraction a/b and we write it as a : b. In the ratio a : b, we call a as… ### SIMPLE INTEREST

Principal: The money borrowed or lent out for a certain period is called the principal or the sum. Interest: Extra money paid for using other’s money is called interest. Simple Interest (S.I.): If the interest… ### GENERAL SCIENCE VII

VARIOUS PROCESSES Chemical union of two or more molecules of the compound to form larger molecules is called Polymerization. The process by which plants take food is photosynthesis Reduction is the removal of oxygen atoms… ### GENERAL SCIENCE II

FACTS ABOUT HUMAN BODY Normal temperature of body is 98.4 deg: F = 37 deg: C Corrine is used as paralyzing agent A nerve cell is called neuron. Each neuron has several inputs called dendrites…