R S Aggarwal Solutions for Exercise 1: EXERCISE 3A

Solve $\left|x\right|\ge 5, x\in R$

Solve $|4x-5|\le \frac{1}{3}, x\in R$

Solve $|5-2x|\le 3, x\in R$

Solve $|3x-7|>4, x\in R$

Solve $\left|\frac{2(3-x)}{5}\right|<\frac{9}{5}, x\in R$

The water acidity in a pool is considered normal when the average pH reading of three daily measurements is between $7.1$ and $7.8$. If first two pH readings are $7.45$ and $7.75$, find the range of pH value for the third reading that will result in, the acidity level being normal.

A company manufactures cassettes and its cost equation for a week is $C=300+1.5x$ and its revenue equation is $R=2x$, where $x$ is the number of cassettes sold in a week. How many least number of cassettes must be sold for the company to realise a profit?

While drilling a hole in the earth, it was found that the temperature$\left(T°C\right)$ at $x$ km below the surface of the earth was given by $T=30+25(x-3),\text{ when }3\le x\le 15$. Between which depths will the temperature be between $200°C$ and $300°C$?