Question

What is the least number which when divided by each one of 6,9,15,18 leaves remainder 4 in each case and completely divisible by 7

Answer 1

LCM (6, 9,15 & 18) + 4

= 180 + 4

= 184

BUT IT MUST BE ALSO DIVISIBLE BY 7

sO WE CAN SAY THAT NUMBER IS 180k+4

180K+4

= 175K+5K+4

175K IS DIVISIBLE BY 7

SO PUT ANY VALUE OF K IN 5K+ 4 SO THAT IT WILL BE DIVISIBLE BY 7

HENCE K = 2

ANSWER IS 180*2+4 = 364

Answer 2

solve this using division method