plsss find these ques 17 18 19 and 20 .
Answers
Answer:
you've only posted questions of 19 & 20 so I'll help you with them.
19) i)
they're asking for the amount that rs.8,000 @5% p.a. C.I. will be at the end of 2nd year.
so, at the end of 1st year that rs.8,000 will be after 5% interest is = rs.8000 + (5% of rs.8000) = rs. 8000 + rs400 =rs.8,400 .
since this is COMPOUND interest (compounded annually), for the next years the 5% will be applied on the preceeding year's total amount.
so, at the end of 2nd year, the amount will be,
rs 8400 + 5% of rs8400 = rs.8400 + rs420
= rs.8820.
19) ii) interest for the 3rd yr.
they're not asking for the total amount, they're asking only for interest amount which will be 5% of rs8820 (total amount standing at the end of 2md year).
so, 5% of rs8820 = rs.441
20) in sum 20, we FIRST have to find out what that sum of money is. they've said 9% of some unknown amount (let's consider that as x) is rs.450 in 2 yrs. so first question is, 9% of what number =450 ?
there's an easy method to figure this out, just do this-
450 ÷ 0.09 (0.09 because 9% is 9/100 which is 0.09)
this will give you the answer as Rs.5000. so rs.5000 is the sum amount of which rs. 450 is the 9% of.
let's reverse check to prove this method is correct-
5000 × 9% = 450. hence proven.
now that we know the sum amount, we can proceed to find the C.I. on it.
now they're asking to apply the same rate of interest, ie, 9%, for 1 yr on this sum amount which is rs.5000. but now they've mentioned that the interest will be applicable half yearly instead of annually.
in simple words, a year got split into 2 halves so now split the 9% into 2 as well , that is, 4.5%.
so,
5000 + 4.5% on 5000 = rs. 5,225 (half a year)
then at the end of the year,
5225 + 4.5% on 5225 = rs. 5,460.10 (round off)
therefore the C.I. for 1 yr compounded annually = 225 + 235.10 = 460.10
(hope my answer was helpful to you, if you liked my answer please mark it the brainliest I'll be very grateful!!!)