IBPS Clerk Mains 29 Nov 2025 Paper

Concept:When equal volumes of two mixtures are mixed, the total parts in the final mixture equal the sum of the parts from each jar.Explanation:Let Jar A have milk : water = $3 : X$.So total parts in Jar A = $3 + X$.Jar B has milk : water = $7 : 5$, so total parts = $12$.Take equal volume $V$ from both jars.Milk in final mixture from A = $\frac{3}{3+X}V$ and from B = $\frac{7}{12}V$.Water in final mixture from A = $\frac{X}{3+X}V$ and from B = $\frac{5}{12}V$.The final ratio is given as $13 : 11$.So, $\frac{\frac{3}{3+X}+\frac{7}{12}}{\frac{X}{3+X}+\frac{5}{12}} = \frac{13}{11}$.Multiply numerator and denominator by $12(3+X)$:$\frac{36 + 7(3+X)}{12X + 5(3+X)} = \frac{13}{11}$.This gives $\frac{57 + 7X}{17X + 15} = \frac{13}{11}$.Cross-multiplying: $11(57 + 7X) = 13(17X + 15)$.So, $627 + 77X = 221X + 195$.Hence, $432 = 144X$, giving $X = 3$.Answer:$X = 3$, which matches option B.