Skip to content
Exercises · Q10

Q.A sum of ₹5,000 is divided between two people such that twice the first person's share exceeds the second person's share by ₹1,000. Using Cramer's Rule, find each person's share.

West Bengal WbchseTextbookSubjectiveImportance★★★★★est
30% · 3/10 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

Setting up the equations

Let xx = the first person's share and yy = the second person's share (both in rupees). The problem states:

x+y=5000x+y=5000

2x−y=1000(twice the first share EXCEEDS the second by ₹1,000)2x-y=1000 \quad(\text{twice the first share EXCEEDS the second by ₹1,000})

Forming DD

D=∣112−1∣=1(−1)−1(2)=−1−2=−3D=\begin{vmatrix}1&1\\2&-1\end{vmatrix}=1(-1)-1(2)=-1-2=-3

Since D≠0D\neq0, a unique solution exists.

Forming DxD_x

Dx=∣500011000−1∣=5000(−1)−1(1000)=−5000−1000=−6000D_x=\begin{vmatrix}5000&1\\1000&-1\end{vmatrix}=5000(-1)-1(1000)=-5000-1000=-6000

Forming DyD_y

Dy=∣1500021000∣=1(1000)−5000(2)=1000−10000=−9000D_y=\begin{vmatrix}1&5000\\2&1000\end{vmatrix}=1(1000)-5000(2)=1000-10000=-9000

Solving

x=−6000−3=2000y=−9000−3=3000x=\frac{-6000}{-3}=2000 \qquad y=\frac{-9000}{-3}=3000

So the first person receives ₹2,000 and the second person receives ₹3,000. …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.