Question

It a=8, then a + 19 = 8 + 19 = 27.
Hence, the greatest values of a and b are 8 and 5 respectively, and the number
Exercise 2.2
1. Test the divisibility by 2,3,5 and 9.
(a) 80+9
(b) 400+70+ 5
(c) 9000 + 600+20+1
2. Find the least value of bin 900 +10b+6 to make it divisible by 3 and 9 both.
3. Give two examples of a number which is divisib! by:
(a) 3 but not 9
(b) 2 but not 6
(c) 2 and 4 but not 8.
4. Write down all the possible numbers, which are divisible by 2, using the digits 3,9, 0 and 2 only once.
5. Using the tests of divisibility, determine which of the following numbers are divisible by 9:
(a) 1258
(b) 4338
(c) 7905
(d) 63909
6. Write the smallest and the greatest values of a in each of the following numbers so that the number formed is
divisible by 3:
(a) a6724
(b) 4765a2
7. Write the values of a andb in the following odd numbers so that the numbers formed are divisible by 3 and 5:
(a) 7a25
(b) 8ab4b
8. Place the digit 1 to 9 in the circle so that the sum of three numbers on each
diameter equals 15.
9. Find the least value of C'in 900 + 30+C to make it divisible by 5 and 10 bath.
0. A number 600+30+C is multiplied by 3 to get a number exactly divisible by 9 find the value
of C.
CHAPTER SUMMARY​

Answer 1

Answer:

1) a) 80+9=89

• then divisibility of two : if the last number has 0,2,4,6,8,theb sits divisible but it's not having those no so it isn't divisible by two
• divisibility by 3 : adding all numbers and getting the final no as a divisible of 3 so, 8+9=17=7+1=8,but 8 is not divisible by 3 then it is not divisible by 3
• divisibility by 5:last digit should be 5 or 0 but it is 9 so 89is not divisible by 5
• divisilbility of 9:as same as divisible of 3 but it should be divisive by 9. so, 8+9=17=1+7=8. so 89 is not divisible by 9