The arithmetic way

Find the 7th term of an arithmetic sequence with 7 as both its first term ad common difference.

• 21
• 35
• 14
• 49

Answer explanation

A gardener is making a triangular planting, with 35 plants in the front row, 31 in the second row, 27 in the third row, and so on. If the pattern is consistent, how many plants will there be in the last row?                                                                                    

• 3

• 7

• 11

• 15

Answer explanation

It's the least positive number of plants.

Cassie earned Php2000 on the first week that she opened her sari-sari store. She wants to increase her earnings by Php200 more every week. If Cassie meets her desired earnings, how much total earnings will she make in three months?

• Php21,600

• Php37,200

• Php38,000

• Php40,000

An auditorium has 20 seats in the first row, 24 seats in the second row, 28 seats in the third row, and so on, for 15 rows. How many seats are there in the last row?

• 32

• 40

• 52

• 76

Answer explanation

Yes! It's the number of seats in the 15th row.

If three arithmetic means are inserted between 11 and 39, find the second arithmetic mean.

• 46

• 32

• 25

• 18

Answer explanation

Don't be confused. We are looking for the second arithmetic mean, not the second term.

Which of the following is the sum of the multiples of 3 from 15 to 48?

• 315

• 360

• 378

• 396

Answer explanation

Answer explanation

The common difference implies the trend of the graph..

Which term of the arithmetic sequence 4, 1, -2, -, …is -29?

Answer explanation

What is the sum of all the odd integers between 8 and 26?

• 153

• 151

• 149

• 148

Answer explanation

That's right! Odd numbers between 8 and 26 are: 9, 11, 13, 15, …25. Using the formula in finding the sum of the arithmetic series, we get 153.

How many poles will be in a pile if there are 50 in the first layer, 49 in the second, and so on, until there are 6 in the last layer?

• The total number of poles will be 1260.

• The total number of poles will be 1225.
• The total number of poles will be 1000.
• The total number of poles will be 1300.

Answer explanation

It's SUM formula!