The average (arithmetic mean) length per film for a group of 25 films is s minutes. If a film that runs for 70 minutes is removed from the group and replaced by one that runs for 50 minutes, what is the average length per film, in minutes, for the new group of films, in terms of s?

Answer Choices

Correct answer marked below

s + 1/5

s - 4/5

Correct

25s + 20

s + 2

s - 2

See the full step-by-step explanation

You can see the correct answer above. Sign in for free to unlock the complete worked solution.

Track your performance and improve

Get detailed analytics, unlock full explanations, and move up difficulty tiers as you practice.

Start for free Sign in

Explanation

Preview

Official Explanation

Official

To find the new average length per film after replacing one film with another, we start with the original average length, which is s minutes for 25 films. The total length of the original 25 films is 25s minutes. When we remove the 70-minute film, the total length becomes 25s - 70 minutes. Then,…

Read the full explanation

Create free account Sign in

Comments

PalakApr 30, 2025

Thank for sharing!

LangMar 22, 2025

this pattern comes up frequently

PrathameshJun 30, 2024

Can you explain more?

PranavOct 22, 2024

thanks for the answer

What this question tests

What it tests

Your ability to manipulate linear and quadratic expressions, substitute unknowns, and solve equations under time pressure.

Common trap

Losing a sign when moving terms across the equals sign, or dividing both sides by a variable that could equal zero.