Math, asked by dassfrefire, 5 months ago

In an A.P. the first term is 1 and the common difference is 4. How many terms of the A.P. must be taken for their sum to be equal to 120 ?

Answers

Answered by HariShukla

1

Answer:

8

Step-by-step explanation:

put the formula

Sn = n/2 [2a +(n-1) d]

put the values

a quadratic eqn. will b form

solve it

get 2 ans.

1) -15/2

2) 8

ans. can't be -ve so 8 will be the answer

Previous Question

Next Question

Similar questions

Hindi, 2 months ago

Fill in the blanks with a, an and the. 1. The first known calculators was_______abacus. 2. Charles Babbage invented l____parts of____ moder computer.

Math, 2 months ago

Choose the singleton set from the following sets (A) {x/x€Z,-1<x<1} (B) {x/x€Z,-1<x<1} (C){ x/x€Z,,-1<x<1} (D){x/x€Z,,-1<x<1}...

Science, 2 months ago

an office uses 6 bulbs of 25 watt each and 2 fans of 100 watt each for 10 hours daily the office is open in all days If the cost of electricity is rs 5 per unit what is the monthly expenditure of electricity...

Math, 5 months ago

in a building there are 25 Central pillars a diameter of each pillar is 56 cm and height is 7 metre find the total cost of painting the curved surface area of all pillar at the rate of 20 per metre square...

English, 5 months ago

_ you have a great day.( insert suitable auxiliaries)...

Hindi, 11 months ago

Aaj exam hai please important hai batado.......Aag(fire) ka pad parichay ....class 10 hindi course a...

English, 11 months ago

If he had worked hard,he......(score)good marks in exams.(use correct form of the verb)...

Social Sciences, 11 months ago

POOJA INTERNATIONAL SCHOOL CLASS 09 - SOCIAL SCIENCE worksheet (Socia) ime Allowed these and 30 minutes Section The duty to protect citizens natural rights was vested to whom? a) Kings b) Lawyers o state ) Court officials 2 Reign of Terror ended with the end of which person? a) Napolean b) Robespierre c) Louis XVI d) John Locke 1 What is the old Regime? a) The society and institutions of by The...