A and B are two number when divided by 7 leaves a remainder 3 and 5. What will be the remainder when A-B is divided by 7 ?



A and B are two number when divided by 7 leaves a remainder 3 and 5. What will be the remainder when A-B is divided by 7 ?

A. 4

B. 5

C. 6

D. 7

Answer : B. 5


Explanation:


    A = 7x + 3,
    B = 7y + 5
    A - B = 7(x - y) - 2
    A - B = 7(x - y) - 7 + 7 – 2 [By adding -7 and +7]
    A - B = 7(x - y - 1) + 5
    As seen above, if we divide A-B by 7, the remainder will be 5.



A and B are two number when divided by 7 leaves a remainder 3 and 5.What will be the remainder when A-B is divided by 7 ?