total sandwiches = 7x
crabs = 3x
salmon = 7x/5
sold y crabs, and then
3x-y = 7x/5 + 42 = 7x - 3x - 7/5 x
solve that to get x = 35 and y=14
so 14 crabs were sold.
check:
to start, there were 105 crabs, 49 salmon, 91 mayo
after the changes, there were
105-14 = 91 crabs
49+42 = 91 salmon
and still 91 mayo
A convenience store sold crabstick, salmon and egg mayo sandwiches. The ratio of the number of crabstick sandwiches made to the total number of sandwiches made was 3:7. The ratio of the number of salmon sandwiches made to the total number of sandwiches made was 1:5. After the store sold some crabstick sandwiches and made another 42 salmon sandwiches, there was an equal number of crabstick, salmon and egg mayo sandwiches left. Find the number of crabstick sandwiches sold
1 answer