There are ‘m’ points on a straight line AB and 'n' points on another straight line AC in which A is not in included. By joining these points triangles are constructed. case i) When A is included. case ii) When A is not included, the ratio of number of triangles in both cases is

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

$\frac{m + n - 2}{2}$

$\frac{m + n - 2}{m + n + 2}$

$\frac{m + n - 2}{m + n}$

$\frac{m + n + 2}{m + n - 2}$

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

When A is not included, the number of triangles formed= $^{m} C_{2} .^{n} C_{1} +^{m} C_{1} .^{n} C_{2}$ When A is included, the number of triangles formed = $^{m} C_{2} .^{n} C_{1} +^{m} C_{1} .^{n} C_{2} +^{m} C_{1} .^{n} C_{1}$

Ratio= $\frac{^{m} C_{2} .^{n} C_{1} +^{m} C_{1} .^{n} C_{2}}{^{m} C_{2} .^{n} C_{1} +^{m} C_{1} .^{n} C_{2} +^{m} C_{1} .^{n} C_{1}} = \frac{\frac{m n}{2} (m - 1 + n - 1)}{\frac{m n}{2} (m - 1 + n - 1 + 2)} = \frac{m + n - 2}{m + n}$

Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

🔥 Start Your JEE/NEET Prep at Just ₹1999 / month - Limited Offer! Check Now!

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET