Question 77

The smallest number among
$$\sqrt[3]{4}, \sqrt[5]{7}, \sqrt[4]{5}, \sqrt{3}$$ is

Solution :

we need to find the LCM of roots' power i.e. LCM of 3,5,4,2 i.e. 60

$$\sqrt[3]{4}$$ =$$4^{\frac{1}{3}}\ =\ 4^{\left(\frac{20}{60}\right)}$$  =  $$\left(4^{50}\right)^{\frac{1}{60}}$$

$$\sqrt[5]{7}$$ =$$7^{\frac{1}{5}}\ =\ 7^{\left(\frac{12}{60}\right)}$$  = $$\left(7^{12}\right)^{\frac{1}{60}}$$

$$\sqrt[4]{5}$$ =$$5^{\frac{1}{4}}\ =\ 5^{\left(\frac{15}{60}\right)}$$  = $$\left(5^{15}\right)^{\frac{1}{60}}$$

 $$\sqrt[2]{3}$$ =$$3^{\frac{1}{2}}\ =\ 3^{\left(\frac{30}{60}\right)}$$ = $$\left(3^{30}\right)^{\frac{1}{60}}$$

As all the external powers are same, we just need to arrange the internal powers in ascending order to find the lowest one.

On careful observation, and also relying on the fact that 7 has the lowest power.  $$\sqrt[5]{7}$$  is the lowest one.Answer.

Get AI Help

Create a FREE account and get:

  • Download Maths Shortcuts PDF
  • Get 300+ previous papers with solutions PDF
  • 500+ Online Tests for Free

Join CAT 2026 course by 5-Time CAT 100%iler

Crack CAT 2026 & Other Exams with Cracku!

Ask AI

Ask our AI anything

AI can make mistakes. Please verify important information.