Question

50

1. Find out the LCM of the following numbers.

(1) 9, 15 (2) 2, 3, 5 (3) 12, 28 (4) 15, 20 (5) 8, 11

2. Solve the following problems.

(1) On the playground, if the children are made to stand for drill either 20 to a row

or 25 to a row, all rows are complete and no child is left out. What is the lowest

possible number of children in that school?

(2) Veena has some beads. She wants to make necklaces with an equal number of

beads in each. If she makes necklaces of 16 or 24 or 40 beads, there is no bead

left over. What is the least number of beads with her?

(3) An equal number of laddoos have been placed in 3 different boxes. The laddoos

in the first box were distributed among 20 children equally, the laddoos in the

second box among 24 children and those in the third box among 12 children. Not

a single laddoo was left over. Then, what was the minimum number of laddoos

in the three boxes altogether?

(4) We observed the traffic lights at three different squares on the same big road. They

turn green every 60 seconds, 120 seconds and 24 seconds. When the signals were

switched on at 8 o’clock in the morning, all the lights were green. How long after

that will all three signals turn green simultaneously again?

(5) Given the fractions

13
/45 and

22/75write their equivalent fractions with same

denominators and add the fractions.

Answer 1

1(1) 3×3×5 (2) 2×3×5 (3) 2×2×3×7