15 - 8
8 + 2 is 10, so there are 5 leftover. 2 + 5 is 7, so 8 + 7 is 15.
Q57) if 1/4 of a packet cover 1/5 then using a packet is using 4* 1/4 of it. This means that 4*1/5 of the garden would be covered which = 4/5.
q58) the total is 24 and 9 of them are boys. Therefore it follows that 9/24 of them are boys and so thats the probability of choosing a boy at random.
image ????? please attach image and try again