What is the sum of the arithmetic sequence 153, 139, 125, if there are 22 terms?

Sum of the sequence = 132.

Step-by-step explanation:

The given sequence is 153, 139, 125,n terms.

Sum of the arithmetic sequence will be

S = n/2[2a + (n -1)d]

where n = number of terms

a = first term of the sequence

d = common difference

for the given sequence

a = 153

n = 22

d = 139 - 153 = -14

Therefore sum of 22 terms of the sequence will be

S = (22/2)[2×153 - (22-1)14]

= 11×[306 - 21×14]

= 11×[306 - 294] = 11×12 = 132

Sum of 22 terms of this sequence is 132.

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

the answers c