2017 · Q109
The average of 7 consecutive odd numbers is M. If the next 3 odd numbers are also included, the average
general-mental-abilityquantitative-aptitude
- Aremains unchanged
- Bincreases by 1.5
- Cincreases by 2
- Dincreases by 3
Explanation
Seven consecutive odd numbers with average M are M−6, …, M+6. Adding the next three odd numbers (M+8, M+10, M+12) gives a new average of (7M + 3M + 30)/10 = M + 3 – an increase of 3. Hence (D).