Question

Ravi ate 2/7 part of the cake while his sister ate 4/5 of the remaining. What part of the cake is left?

Answer 1

Let the total cake be 'a'

Ravi ate 2/7a

Cake left = a - 2/7a = 5/7a

Now from 5/7a his sister ate 4/5 of it
So His sister ate = 5/7a x 4/5 = 4/7a

Now cake left = 5/7a - 4/7a = 1/7a

So required answer is 1/7

Hope This Helps You!

Answer 2

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Let the total cake be 'a'

Ravi ate 2/7a

Cake left = a - 2/7a = 5/7a

Now from 5/7a his sister ate 4/5 of it

So His sister ate = 5/7a x 4/5 = 4/7a

Now cake left = 5/7a - 4/7a = 1/7a

So required answer is 1/7