There are 50 students admitted to a nursery class. Some students, can speak only English and some can speak only Hindi. 10 students can speak both English and Hindi. If the number of students who can speak English is 21, then how many students can speak Hindi, how many can speak only Hindi and how many can speak only English?

To solve this efficiently, I look at what the question asks for: a list of three numbers (Total Hindi, Only Hindi, Only English).\n\n1. **Identify the easiest target:** Calculating 'Total Hindi' or 'Only Hindi' requires deducing the remaining students from the total 50. However, calculating 'Only English' is much more direct because we already have the 'Total English' count.\n\n2. **Calculate Only English:**\n * Total English = 21\n * Both English and Hindi = 10\n * Therefore, Only English = 21 - 10 = 11.\n\n3. **Eliminate Options:**\n I need an option that *ends* with 11.\n * (A) Ends in 29\n * (B) Ends in 22\n * (C) Ends in 13\n * (D) Ends in 11\n\n Only Option (D) fits. I don't need to calculate the Hindi numbers at all. This saves significant time and effort.