Math Problem Solver

During the math class, a teacher clears the concept of permutation and combination to the 11th standard students. After the

class was over she asks the students some questions, one of the question was: how many numbers between 99 and 1000 (bothexcluding) can be formed such that

i. Every digit is either 3 or 7.

8 ways

d. 16 ways

b. 2 ways

c. 27 ways

ii.There is no restriction.

a.1000ways

b.900ways

c.800ways

d.700ways

iii. No digit is repeated.

a.684 ways

b. 600 ways

d. 729 ways

c. 648 ways

iv. The digit in hundred's place is 7.

a.70

b.80

c.90

d.100

At least one of the digits is 7.

a.252 ways

b. 525 ways

c. 200 ways

d. 500 ways

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