7. Two bells ring at an interval of 30 minutes and 40 minutes to change the lessons in lower and upper primary respectively,
a) After how long will they ring together at the same time?
b) If they first ring together at 9:15 a. m. at what time will they ring together again?​

Ionic compounds dissociate into component ions dissolved into a solution creating substances called "electrolytes".hope my answer has you : )

H tricky one let me think and get back to u

1. why does the same side of the moon always face earthc.the rotational period of the moon is equal to one revolution around earth2. which is greater the moons period of rotation or its period of revolution  b.the moons revolution period around earth3.what was the major accomplishment of the apollo missions  d.landing on and exploring the moon4. which of these space missions involved the deployment of lunar rovers d.apollo5. which scientists are going to explore next on kepler-186fd. evidence of existence of life6.which mission is not going to explore the outside of the solar systemb.safir7.which technology limit the future of space exploration b. scientist must first develop certain technologies before missions can be completed.