RRB Group-D Model Paper 13 with answers for online practice

To solve questions of this type, follow the laws of “Surds and indices’’ given below:
Laws of Indices:
1. ${\mathit{a}}^{\mathit{m}}\times {\mathit{a}}^{\mathit{n}}={\mathit{a}}^{\mathit{m}+\mathit{n}}$
2. ${\mathit{a}}^{\mathit{m}}÷{\mathit{a}}^{\mathit{n}}={\mathit{a}}^{\mathit{m}-\mathit{n}}$
3. ${\left({\mathit{a}}^{\mathit{m}}\right)}^{\mathit{n}}={\mathit{a}}^{\mathit{m}\mathit{n}}$
4. ${\left(\mathit{a}\right)}^{-\mathit{m}}=\frac{1}{{\mathit{a}}^{\mathit{m}}}$
5. ${\left(\mathit{a}\right)}^{\frac{\mathit{m}}{\mathit{n}}}=\mathit{n}\sqrt{{\mathit{a}}^{\mathit{m}}}$
6. ${\left(\mathit{a}\right)}^0=1$
${625}^{0.17}\times {625}^{0.08}={25}^{?}\times {25}^{-\frac{3}{2}}$
⇒ ${625}^{0.17+0.08}={25}^{?+\left(-32\right)}$
⇒ ${625}^{0.25}={25}^{?-32}$
⇒ ${625}^{\frac{1}{4}}={\left(5^2\right)}^{?-32}$
⇒ $5=5^{2\times ?-3}$
⇒ 2 × ? - 3 = 1
⇒ ? = (1 + 3)/2
∴ ? = 2