Answer:
Step-by-step explanation:
<u>Given AP with:</u>
- a₁= 28, aₙ = 79, Sₙ = 963
<u>Use the formula:</u>
- Sₙ = 1/2n(a₁ + aₙ), sum of the first n terms
<u>Substitute given values and solve for n:</u>
- 963 = 1/2n(28 + 79)
- 963 = 1/2n(107)
- 1/2n = 963/107
- 1/2n = 9
- n = 9*2
- n = 18
What you need to is find out how much 3/8 is, compared to 3/4. since 4 is half of 8 you have to multiply 3/4 by 2, which gives you 6/8. 6/8 is greater than 3/8, therefore Mariah ran farther
2 + 6 = 8. 2 is left. 6 is left.
