Step-by-step explanation:
the distributing ratio is 2:5.
that means for every 2 white marbles there must be 5 blue marbles.
so, we are taking about "groups" or multiples of 7 (2+5 = 7).
now, even 7×7 = 49 is too small.
but the next multiple of 7 (7×8 = 56) is now big enough to include at least 50 marbles.
so, in order to keep the 2:5 ratio strictly in place, the minimum number of marbles in the bag is 56.
