ICSE Class 9 Mathematics — Flashcards for Quick Revision

A: A rational number is a number that can be expressed as a/b, where 'a' and 'b' are both integers and 'b' ≠ 0. The set of rational numbers is denoted by Q. Examples: 3/4, -5/7, 0, 2 (which is 2/1).

A: (i) b ≠ 0 (ii) a and b have no common factor other than 1 (they are co-primes) (iii) b is usually positive, while a may be positive, negative, or zero.

A: Step 1: Find d = (y-x)/(n+1). Step 2: The n rational numbers are: x+d, x+2d, x+3d, ..., x+nd. Example: To insert 2 numbers between 1 and 4: d = (4-1)/(2+1) = 1, so numbers are 2 and 3.

A: Interest is the extra money paid for using someone else's money. When you borrow money (principal), you must return the original amount plus interest. The total money paid back is called the amount. F

A: Simple Interest is calculated on the original principal throughout the entire loan period, regardless of how long the money is borrowed. The interest remains the same every year. Formula: S.I. = (P ×

A: Compound Interest is when the interest earned is added to the principal at the end of each period, and this new amount becomes the principal for the next period. Unlike Simple Interest, the principal

A: A = P(1 + r/100)ⁿ Where: A = Amount P = Principal r = Rate of interest per annum n = Number of years This formula helps us calculate the total amount after compound interest without finding CI separ

A: C.I. = P[(1 + r/100)ⁿ - 1] Or alternatively: C.I. = A - P The first formula directly gives compound interest without calculating amount first. The second requires finding amount first and then subtr

A: Given: P = ₹5,000, n = 2 years, r = 8% Using A = P(1 + r/100)ⁿ A = ₹5,000(1 + 8/100)² A = ₹5,000(1.08)² A = ₹5,000 × 1.1664 A = ₹5,832 Therefore, Amount = ₹5,832