Today's Daily Quiz is Live — Test your knowledge & improve your rank
|
Mathematical Puzzles Expert 2 min

A sequence is defined by a₁ = 3 and aₙ = aₙ₋₁ + 4. What is a₁₀?

Hint
This is an arithmetic sequence.

Answer

39.

Explanation

The tenth term is 3 + 9×4 = 39.

Step-by-Step Solution

a₁₀ = a₁ + 9d.
= 3 + 9×4.
= 39.
6 puzzles
The sum of two numbers is 84 and their difference is 18. What is the larger number?
26 views Mathematical Puzzles
Medium
A number is 30% less than 200. What is the number?
17 views Mathematical Puzzles
Hard
The product of two consecutive positive integers is 156. What are the integers?
15 views Mathematical Puzzles
Hard
A three-digit number has digits whose sum is 12. The hundreds digit is twice the tens digit, and the units digit is three more than the tens digit. What is the number?
16 views Mathematical Puzzles
Expert
A tank contains 90 litres of water. One-third of the water is removed and replaced with an equal amount of clean water. How much of the original water remains?
19 views Mathematical Puzzles
Hard
The average of five numbers is 24. Four of the numbers are 18, 22, 25 and 30. What is the fifth number?
10 views Mathematical Puzzles
Medium