Q) In a 2-digit number, the digit at the unit’s place is 5 less than the digit at the ten’s place. The product of the digits is 36. Find the number. Ans: Let’s consider X is the digit at unit’s place and Y is the digit at ten’s place. The number will be 10 Y + […]
In a 2-digit number, the digit at the unit’s place is 5 less than the digit Read More »
Q) Tara scored 40 marks in a test, getting 3 marks for each right answer and losing 1 mark for each wrong answer. Had 4 marks been awarded for each correct answer and 2 marks been deducted for each wrong answer, then Tara would have scored 50 marks. Assuming that Tara attempted all questions, find
Tara scored 40 marks in a test, getting 3 marks for each right answer and losing Read More »
Q) The sum of the digits of a 2-digit number is 14. The number obtained by interchanging its digits exceeds the given number by 18. Find the number. Ans: Let’s consider X and Y are the digits of the given number. Hence the given number is 10 X + Y ∴ the sum of the digits
Q) Solve the following system of linear equations : 2 x + 5 y = – 4 and 4 x – 3 y = 5 Ans: Given equations are: 2 x + 5 y = – 4 …………………… (i) 4 x – 3 y = 5 …………………..(ii) To get the value of variables, we need to
Solve the following system of linear equations : 2 x + 5 y = – 4 and 4 x – 3 y = 5 Read More »
Q) Solve the following system of linear equations : 7 x – 2 y = 5 and 8 x + 7 y = 15 and verify your answer. Ans: Given equations are: 7 x – 2 y = 5 …………………… (i) 8 x + 7 y = 15 …………………..(ii) To get the value of variables,
Q) Solve the following system of linear equations : 2p + 3q = 13 and 5p – 4q = – 2 Ans: Given equations are: 2p + 3q = 13 …… ………….. (i) and 5p – 4q = – 2 …………… (ii) To get the value of variables, we need to drop one variable. Let’s
Solve the following system of linear equations : 2p + 3q = 13 Read More »
Q) In a chemistry lab, there is some quantity of 50% acid solution and some quantity of 25% acid solution. How much of each should be mixed to make 10 litres of 40% acid solution? Ans: Let consider quantity of 50% acid solution be V litres ∵ total quantity of final solution is 10 litres ∴
In a chemistry lab, there is some quantity of 50% acid solution and some quantity of 25% Read More »
Q) The monthly incomes of A and B are in the ratio 8 : 7 and their expenditures are in the ratio 19 : 16. If each saves 2500 per month, find the monthly income of each. Ans: Let the income of A and B be 8 X and 7 X Since Saving = Income
Q) Solve the following pair of linear equations: Ans: Given the equations: ……….. (i) ………….(ii) Step 1: Let’s multiply equation (i) by b2 and add to equation (ii), we get: ……….. (i) ∴ ……….. (i) ∴ ……….. (i) ∴ b2 x + a2 x = a ( a2 + b2 ) ∴ x (a2 + b2
Solve the following pair of linear equations: x/a – y/b =0, a x + b y = a2 + b2 Read More »
Q) Solve the following pair of linear equations: (a – b) x + (a + b) y = a2 – 2 a b – b2 (a + b) (x + y) = a2 + b2 Ans: Given the equations: (a – b) x + (a + b) y = a2 – 2 a b – b2……