You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[EX Q]: Question: How many odd 4-digit positive integers R that are multiples of 5 can be formed without using the digit 3?

Option A: 648

Option B: 729

Option C: 900

Option D: 1296

Option E: 3240
[EX A]: Option A

[EX Q]: Question: A bus takes 3 hours to cover a distance of 500 Km. how much should the speed in Kmph be maintained to cover the same direction in 5/3th of the previous time?

Option A: 75 Kmph

Option B: 100 Kmph

Option C: 90 Kmph

Option D: 65 Kmph

Option E: 70 Kmph
[EX A]: Option B

[EX Q]: Question: A firm has 2 senior partners and 5 junior partners. How many different groups of 3 partners can be formed in which at least one member of the group is a senior partner? (Note that two groups are considered different if at least one group member is different.)

Option A: 17

Option B: 21

Option C: 25

Option D: 29

Option E: 33
[EX A]:
Option C