Question
The 5th and 8th term of an arithmetic progression are 13
and -5 respectively. What is the 15th term?Solution
Given: 5th term a5 = 13, 8th term a8 = −5.
Use the formula: The formula for the n-th term is: 
Solve the system of equations: Subtract the first equation from the second: 3d = −18 ⇒ d = − 6 Substitute d = − 6 into a1+ 4d = 13: 
Find the 15th term:
The 15th term is -47.
Neha deposited Rs. 35,000 on compound interest at 10% per annum compounded annually for 3 years, while Meha deposited Rs. 50,000 on simple interest at 1...
An amount of Rs. 2400 is placed in SIP 'P' at a 25% per annum simple interest rate for 8 years, and Rs. 2500 is invested in SIP 'Q' with a 20% annual co...
- P deposits ₹(A - 10,000) in a bank at an interest rate of 10% per annum, compounded half-yearly, for 1 year. Meanwhile, Q invests ₹(A + 15,000) in the ...
A sum when invested at simple interest of 12% p.a. becomes Rs. 2,080 in 5 years.
If the same sum was invested at compound interest of 20% p.a. fo...When two equal amounts are deposited for 7 years and 5 years at the rate of 6% and 8% per annum respectively, the difference of their simple interest is...
If the ratio of the sum invested and simple interest received after 1 year is 20:13 respectively, then find the rate of interest.
The simple interest received on a sum is 25/36 of the sum. The number of years is equal to the annual rate of interest. What is the annual rate of inte...
Rs. 'x' is invested in scheme 'A' offering simple interest such that interest earned after 5 years is Rs. 600. If the amount received is further investe...
Rs. 6,000 is deposited in Scheme 'X' which provides compound interest at 8% per annum, compounded annually. Another amount of Rs. 5600 is invested in Sc...
Rs. 10000 invested for 2 years in a scheme offering compound interest (compounded annually) of 15% p.a. gives an interest that is Rs. 25 less than the i...
