Question
The sum of the digits of a two-digit number is 9, and
when the digits are reversed, the number decreases by 45. Find the changed number.Solution
Let unit digit be x and ten's digit be y. Original number = x+10y Reversing the digits, new number = 10x+y 
Also, x + y = 9(eq2) Add eq1 and eq2 = 2x = 4, or x = 2 Substitute in eq2 = 2 + y = 9, or y = 7 Hence, Original number = 72
Akshay invested Rs. 960 in two schemes P and Q in the respective ratio of 5:3. Scheme P and Q are offering simple interest at the rate of 7% per annum a...
The interest earned on investing Rs. 9000 for 2 years at the rate of 10% p.a., compounded annually, is used to purchase an article. If the article is la...
Mr. P invested Rs. ‘2x’ in scheme ‘A’ offering simple interest of 20% p.a. and reinvested the interest earned from scheme ‘A’ at the end of ...
A sum of Rs. 9,600 grows to Rs. 12,696 when invested at an annual compound interest rate of 'R%' for 2 years. What is the value of 'R'?
The difference between compound interest and simple interest at the same rate for Rs. 3600 for 2 years is Rs. 36. The rate of interest per annum is:
Roshan and Rahul received marks in their quarterly exam in a ratio of 9:8. Additionally, the ratio of marks Roshan obtained in the quarterly exam to the...
The interest received on investing Rs. (5p + 150) on simple interest at 15% p.a. for 2 years is Rs. (2p + 240). Find the ratio (p - 90):(p + 60)
Suresh earned an interest of Rs. 774 on principal amount of Rs. 2400 at some rate of compound interest in 2 years. How much more/less interest would he ...
A certain sum of money invested at R% p.a. fetches a compound interest (compounded annually) of 1560 and simple interest of Rs.1500 at the end of 2 year...
A man invested a certain amount of sum at 12.5% per annum simple interest and earned an interest of Rs.2100 after 3 years. If the same amount is investe...
Relevant for Exams:
