Question

a tin of oil was 4/5 full. when 7 bottles of oil were taken out and 4 bottles of oil were pored into it, it was 3/4 full. How many bottles of oil can the tin contain?

Answer 1

 6 BOTTLES OUT 4 BOTTLES IN THEREFORE, TOTAL 2 BOTTLES OUT
THEN TIN CAN WAS - 3/4 FULL
IT MEANS 
4/5 OF CAN - 3/4 OF CAN = 2 BOTTLES
LET CAPACITY OF CAN BE x BOTTLESTHEN,
4/5 x - 3/4 x = 2(16 - 15 /20) x = 21 x / 20 = 2x = 2 × 20=> x = 40

THEREFORE, THE CAPACITY OF CAN IS 40 SUCH BOTTLES AND IN THE ORIGINAL STATE IT CONTAINED (4/5 OF 40 ) = 32 BOTTLES OF OIL AND AFTER EXTRACTION CONTAINED (3/4 OF 40) = 30 BOTTLES OF OIL.ANSWER = 40 BOTTLES ( CAPACITY )